Phonetics is a branch of linguistics that studies the sounds of human speech, or—in the case of sign languages—the equivalent aspects of sign. It is concerned with the physical properties of speech sounds or signs: their physiological production, acoustic properties, auditory perception, neurophysiological status. Phonology, on the other hand, is concerned with the abstract, grammatical characterization of systems of sounds or signs. In the case of oral languages, phonetics has three basic areas of study: Articulatory phonetics: the study of the organs of speech and their use in producing speech sounds by the speaker. Acoustic phonetics: the study of the physical transmission of speech sounds from the speaker to the listener. Auditory phonetics: the study of the reception and perception of speech sounds by the listener; the first known phonetic studies were carried out as early as the 6th century BCE by Sanskrit grammarians. The Hindu scholar Pāṇini is among the most well known of these early investigators, whose four part grammar, written around 350 BCE, is influential in modern linguistics and still represents "the most complete generative grammar of any language yet written".
His grammar formed the basis of modern linguistics and described a number of important phonetic principles. Pāṇini provided an account of the phonetics of voicing, describing resonance as being produced either by tone, when vocal folds are closed, or noise, when vocal folds are open; the phonetic principles in the grammar are considered "primitives" in that they are the basis for his theoretical analysis rather than the objects of theoretical analysis themselves, the principles can be inferred from his system of phonology. Advancements in phonetics after Pāṇini and his contemporaries were limited until the modern era, save some limited investigations by Greek and Roman grammarians. In the millenia between Indic grammarians and modern phonetics the focus of phonetics shifted from the difference between spoken and written language, the driving force behind Pāṇini's account, began to focus on the physical properties of speech alone. Sustained interest in phonetics began again around 1800 CE with the term "phonetics" being first used in the present sense in 1841.
With new developments in medicine and the development of audio and visual recording devices, phonetic insights were able to use and review new and more detailed data. This early period of modern phonetics included the development of an influential phonetic alphabet based on articulatory positions by Alexander Melville Bell. Known as visible speech, it gained prominency as a tool in the oral education of deaf children. Speech sounds are produced by the modification of an airstream exhaled from the lungs; the respiratory organs used to create and modify airflow are divided into three regions: the vocal tract, the larynx, the subglottal system. The airstream can be either ingressive. In pulmonic sounds, the airstream is produced by the lungs in the subglottal system and passes through the larynx and vocal tract. Glottalic sounds use. Clicks or lingual ingressive sounds create an airstream using the tongue. Articulations take place in particular parts of the mouth, they are described by the part of the mouth that constricts airflow and by what part of the mouth that constriction occurs.
In most languages constrictions are made with tongue. Constrictions made by the lips are called labials; the tongue can make constrictions with many different parts, broadly classified into coronal and dorsal places of articulation. Coronal articulations are made with either the tip or blade of the tongue, while dorsal articulations are made with the back of the tongue; these divisions are not sufficient for describing all speech sounds. For example, in English the sounds and are both voiceless coronal fricatives, but they are produced in different places of the mouth. Additionally, that difference in place can result in a difference of meaning like in "sack" and "shack". To account for this, articulations are further divided based upon the area of the mouth in which the constriction occurs. Articulations involving the lips can be made in three different ways: with both lips, with one lip and the teeth, with the tongue and the upper lip. Depending on the definition used, some or all of these kinds of articulations may be categorized into the class of labial articulations.
Ladefoged and Maddieson propose that linguolabial articulations be considered coronals rather than labials, but make clear this grouping, like all groupings of articulations, is equivocable and not cleanly divided. Linguolabials are included in this section as labials given their use of the lips as a place of articulation. Bilabial consonants are made with both lips. In producing these sounds the lower lip moves farthest to meet the upper lip, which moves down though in some cases the force from air moving through the aperature may cause the lips to separate faster than they can come together. Unlike most other articulations, both articulators are made from soft tissue, so bilabial stops are more to be produced with incomplete closures than articulations involving hard surfaces like the teeth or palate. Bilabial stops are unusual in that an articulator in the upper section of the vocal tract moves downwards, as the upper lip shows some active downward movement. Labiodental consonants are made by the lower lip rising to the upper teeth.
Labiodental consonants are most fricatives while labiodental nasals are typologically common. There is debate as to
In linguistics, grammar is the set of structural rules governing the composition of clauses and words in any given natural language. The term refers to the study of such rules, this field includes phonology and syntax complemented by phonetics and pragmatics. Speakers of a language have a set of internalized rules for using that language, these rules constitute that language's grammar; the vast majority of the information in the grammar is – at least in the case of one's native language – acquired not by conscious study or instruction, but by observing other speakers. Much of this work is done during early childhood. Thus, grammar is the cognitive information underlying language use; the term "grammar" can be used to describe the rules that govern the linguistic behavior of a group of speakers. The term "English grammar", may have several meanings, it may refer to the whole of English grammar, that is, to the grammars of all the speakers of the language, in which case, the term encompasses a great deal of variation.
Alternatively, it may refer only to what is common to the grammars of all, or of the vast majority of English speakers. Or it may refer to the rules of a particular well-defined variety of English. A specific description, study or analysis of such rules may be referred to as a grammar. A reference book describing the grammar of a language is called a "reference grammar" or "a grammar". A explicit grammar that exhaustively describes the grammatical constructions of a particular lect is called a descriptive grammar; this kind of linguistic description contrasts with linguistic prescription, an attempt to discourage or suppress some grammatical constructions, while codifying and promoting others, either in an absolute sense, or in reference to a standard variety. For example, preposition stranding occurs in Germanic languages, has a long history in English, is considered standard usage. John Dryden, objected to it, leading other English speakers to avoid the construction and discourage its use. Outside linguistics, the term grammar is used in a rather different sense.
In some respects, it may be used more broadly, including rules of spelling and punctuation, which linguists would not consider to form part of grammar, but rather as a part of orthography, the set of conventions used for writing a language. In other respects, it may be used more narrowly, to refer to a set of prescriptive norms only and excluding those aspects of a language's grammar that are not subject to variation or debate on their normative acceptability. Jeremy Butterfield claimed that, for non-linguists, "Grammar is a generic way of referring to any aspect of English that people object to." The word grammar is derived from Greek γραμματικὴ τέχνη, which means "art of letters", from γράμμα, "letter", itself from γράφειν, "to draw, to write". The same Greek root appears in graphics and photograph. Vedic Sanskrit is the earliest language known to the world; the grammatical rules were formulated by Indra, etc. but the modern systematic grammar, of Sanskrit, originated in Iron Age India, with Yaska, Pāṇini and his commentators Pingala and Patanjali.
Tolkāppiyam, the earliest Tamil grammar, is dated to before the 5th century AD. The Babylonians made some early attempts at language description,In the West, grammar emerged as a discipline in Hellenism from the 3rd century BC forward with authors like Rhyanus and Aristarchus of Samothrace; the oldest known grammar handbook is the Art of Grammar, a succinct guide to speaking and writing and written by the ancient Greek scholar Dionysius Thrax, a student of Aristarchus of Samothrace who established a school on the Greek island of Rhodes. Dionysius Thrax's grammar book remained the primary grammar textbook for Greek schoolboys until as late as the twelfth century AD; the Romans based their grammatical writings on it and its basic format remains the basis for grammar guides in many languages today. Latin grammar developed by following Greek models from the 1st century BC, due to the work of authors such as Orbilius Pupillus, Remmius Palaemon, Marcus Valerius Probus, Verrius Flaccus, Aemilius Asper.
A grammar of Irish originated in the 7th century with the Auraicept na n-Éces. Arabic grammar emerged with Abu al-Aswad al-Du'ali in the 7th century; the first treatises on Hebrew grammar appeared in the context of Mishnah. The Karaite tradition originated in Abbasid Baghdad; the Diqduq is one of the earliest grammatical commentaries on the Hebrew Bible. Ibn Barun in the 12th century compares the Hebrew language with Arabic in the Islamic grammatical tradition. Belonging to the trivium of the seven liberal arts, grammar was taught as a core discipline throughout the Middle Ages, following the influence of authors from Late Antiquity, such as Priscian. Treatment of vernaculars began during the High Middle Ages, with isolated works such as the First Grammatical Treatise, but became influential only in the Renaissance and Baroque periods. In 1486, Antonio de Nebrija published Las introduciones Latinas contrapuesto el romance al Latin, the first Spanish grammar, Gramática de la lengua castellana, in 1492.
During the 16th-century Italian Ren
Australia the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It is the world's sixth-largest country by total area; the neighbouring countries are Papua New Guinea and East Timor to the north. The population of 25 million is urbanised and concentrated on the eastern seaboard. Australia's capital is Canberra, its largest city is Sydney; the country's other major metropolitan areas are Melbourne, Brisbane and Adelaide. Australia was inhabited by indigenous Australians for about 60,000 years before the first British settlement in the late 18th century, it is documented. After the European exploration of the continent by Dutch explorers in 1606, who named it New Holland, Australia's eastern half was claimed by Great Britain in 1770 and settled through penal transportation to the colony of New South Wales from 26 January 1788, a date which became Australia's national day; the population grew in subsequent decades, by the 1850s most of the continent had been explored and an additional five self-governing crown colonies established.
On 1 January 1901, the six colonies federated. Australia has since maintained a stable liberal democratic political system that functions as a federal parliamentary constitutional monarchy, comprising six states and ten territories. Being the oldest and driest inhabited continent, with the least fertile soils, Australia has a landmass of 7,617,930 square kilometres. A megadiverse country, its size gives it a wide variety of landscapes, with deserts in the centre, tropical rainforests in the north-east and mountain ranges in the south-east. A gold rush began in Australia in the early 1850s, its population density, 2.8 inhabitants per square kilometre, remains among the lowest in the world. Australia generates its income from various sources including mining-related exports, telecommunications and manufacturing. Indigenous Australian rock art is the oldest and richest in the world, dating as far back as 60,000 years and spread across hundreds of thousands of sites. Australia is a developed country, with the world's 14th-largest economy.
It has a high-income economy, with the world's tenth-highest per capita income. It is a regional power, has the world's 13th-highest military expenditure. Australia has the world's ninth-largest immigrant population, with immigrants accounting for 26% of the population. Having the third-highest human development index and the eighth-highest ranked democracy globally, the country ranks in quality of life, education, economic freedom, civil liberties and political rights, with all its major cities faring well in global comparative livability surveys. Australia is a member of the United Nations, G20, Commonwealth of Nations, ANZUS, Organisation for Economic Co-operation and Development, World Trade Organization, Asia-Pacific Economic Cooperation, Pacific Islands Forum and the ASEAN Plus Six mechanism; the name Australia is derived from the Latin Terra Australis, a name used for a hypothetical continent in the Southern Hemisphere since ancient times. When Europeans first began visiting and mapping Australia in the 17th century, the name Terra Australis was applied to the new territories.
Until the early 19th century, Australia was best known as "New Holland", a name first applied by the Dutch explorer Abel Tasman in 1644 and subsequently anglicised. Terra Australis still saw occasional usage, such as in scientific texts; the name Australia was popularised by the explorer Matthew Flinders, who said it was "more agreeable to the ear, an assimilation to the names of the other great portions of the earth". The first time that Australia appears to have been used was in April 1817, when Governor Lachlan Macquarie acknowledged the receipt of Flinders' charts of Australia from Lord Bathurst. In December 1817, Macquarie recommended to the Colonial Office. In 1824, the Admiralty agreed that the continent should be known by that name; the first official published use of the new name came with the publication in 1830 of The Australia Directory by the Hydrographic Office. Colloquial names for Australia include "Oz" and "the Land Down Under". Other epithets include "the Great Southern Land", "the Lucky Country", "the Sunburnt Country", "the Wide Brown Land".
The latter two both derive from Dorothea Mackellar's 1908 poem "My Country". Human habitation of the Australian continent is estimated to have begun around 65,000 to 70,000 years ago, with the migration of people by land bridges and short sea-crossings from what is now Southeast Asia; these first inhabitants were the ancestors of modern Indigenous Australians. Aboriginal Australian culture is one of the oldest continual civilisations on earth. At the time of first European contact, most Indigenous Australians were hunter-gatherers with complex economies and societies. Recent archaeological finds suggest. Indigenous Australians have an oral culture with spiritual values based on reverence for the land and a belief in the Dreamtime; the Torres Strait Islanders, ethnically Melanesian, obtained their livelihood from seasonal horticulture and the resources of their reefs and seas. The northern coasts and waters of Australia were visited s
Dependency grammar is a class of modern grammatical theories that are all based on the dependency relation and that can be traced back to the work of Lucien Tesnière. Dependency is the notion that linguistic units, e.g. words, are connected to each other by directed links. The verb is taken to be the structural center of clause structure. All other syntactic units are either directly or indirectly connected to the verb in terms of the directed links, which are called dependencies. DGs are distinct from phrase structure grammars, since DGs lack phrasal nodes, although they acknowledge phrases. Structure is determined by the relation between its dependents. Dependency structures are flatter than phrase structures in part because they lack a finite verb phrase constituent, they are thus well suited for the analysis of languages with free word order, such as Czech and Warlpiri; the notion of dependencies between grammatical units has existed since the earliest recorded grammars, e.g. Pāṇini, the dependency concept therefore arguably predates that of phrase structure by many centuries.
Ibn Maḍāʾ, a 12th-century linguist from Córdoba, may have been the first grammarian to use the term dependency in the grammatical sense that we use it today. In early modern times, the dependency concept seems to have coexisted side by side with that of phrase structure, the latter having entered Latin, French and other grammars from the widespread study of term logic of antiquity. Dependency is concretely present in the works of Sámuel Brassai, a Hungarian linguist, Franz Kern, a German philologist, of Heimann Hariton Tiktin, a Romanian linguist. Modern dependency grammars, begin with the work of Lucien Tesnière. Tesnière was a Frenchman, a polyglot, a professor of linguistics at the universities in Strasbourg and Montpellier, his major work Éléments de syntaxe structurale was published posthumously in 1959 – he died in 1954. The basic approach to syntax he developed seems to have been seized upon independently by others in the 1960s and a number of other dependency-based grammars have gained prominence since those early works.
DG has generated a lot of interest in Germany in both theoretical language pedagogy. In recent years, the great development surrounding dependency-based theories has come from computational linguistics and is due, in part, to the influential work that David Hays did in machine translation at the RAND Corporation in the 1950s and 1960s. Dependency-based systems are being used to parse natural language and generate tree banks. Interest in dependency grammar is growing at present, international conferences on dependency linguistics being a recent development. Dependency is a one-to-one correspondence: for every element in the sentence, there is one node in the structure of that sentence that corresponds to that element; the result of this one-to-one correspondence is. All that exist are the dependencies that connect the elements into a structure; this situation should be compared with phrase structure. Phrase structure is a one-to-one-or-more correspondence, which means that, for every element in a sentence, there is one or more nodes in the structure that correspond to that element.
The result of this difference is that dependency structures are minimal compared to their phrase structure counterparts, since they tend to contain many fewer nodes. These trees illustrate two possible ways to render the phrase structure relations; this dependency tree is an "ordered" tree. Many dependency trees abstract away from linear order and focus just on hierarchical order, which means they do not show actual word order; this constituency tree follows the conventions of bare phrase structure, whereby the words themselves are employed as the node labels. The distinction between dependency and phrase structure grammars derives in large part from the initial division of the clause; the phrase structure relation derives from an initial binary division, whereby the clause is split into a subject noun phrase and a predicate verb phrase. This division is present in the basic analysis of the clause that we find in the works of, for instance, Leonard Bloomfield and Noam Chomsky. Tesnière, argued vehemently against this binary division, preferring instead to position the verb as the root of all clause structure.
Tesnière's stance was that the subject-predicate division stems from term logic and has no place in linguistics. The importance of this distinction is that if one acknowledges the initial subject-predicate division in syntax is real one is to go down the path of phrase structure grammar, while if one rejects this division one must consider the verb as the root of all structure, so go down the path of dependency grammar; the following frameworks are dependency-based: Algebraic syntax Operator grammar Link grammar Functional generative description Lexicase Meaning–text theory Word grammar Extensible dependency grammar Universal DependenciesLink grammar is similar to dependency grammar, but link grammar does not include directionality between the linked words, thus does not describe head-dependent relationships. Hybrid dependency/phrase structure grammar uses dependencies between words, but includes dependencies between phrasal nodes – see for example the Quranic Arabic Dependency Treebank; the derivation trees of tree-adjoining grammar are dependency struc
Computational linguistics is an interdisciplinary field concerned with the statistical or rule-based modeling of natural language from a computational perspective, as well as the study of appropriate computational approaches to linguistic questions. Traditionally, computational linguistics was performed by computer scientists who had specialized in the application of computers to the processing of a natural language. Today, computational linguists work as members of interdisciplinary teams, which can include regular linguists, experts in the target language, computer scientists. In general, computational linguistics draws upon the involvement of linguists, computer scientists, experts in artificial intelligence, logicians, cognitive scientists, cognitive psychologists, psycholinguists and neuroscientists, among others. Computational linguistics has applied components. Theoretical computational linguistics focuses on issues in theoretical linguistics and cognitive science, applied computational linguistics focuses on the practical outcome of modeling human language use.
The Association for Computational Linguistics defines computational linguistics as:...the scientific study of language from a computational perspective. Computational linguists are interested in providing computational models of various kinds of linguistic phenomena. Computational linguistics is grouped within the field of artificial intelligence, but was present before the development of artificial intelligence. Computational linguistics originated with efforts in the United States in the 1950s to use computers to automatically translate texts from foreign languages Russian scientific journals, into English. Since computers can make arithmetic calculations much faster and more than humans, it was thought to be only a short matter of time before they could begin to process language. Computational and quantitative methods are used in attempted reconstruction of earlier forms of modern languages and subgrouping modern languages into language families. Earlier methods such as lexicostatistics and glottochronology have been proven to be premature and inaccurate.
However, recent interdisciplinary studies which borrow concepts from biological studies gene mapping, have proved to produce more sophisticated analytical tools and more trustworthy results. When machine translation failed to yield accurate translations right away, automated processing of human languages was recognized as far more complex than had been assumed. Computational linguistics was born as the name of the new field of study devoted to developing algorithms and software for intelligently processing language data; the term "computational linguistics" itself was first coined by David Hays, founding member of both the Association for Computational Linguistics and the International Committee on Computational Linguistics. When artificial intelligence came into existence in the 1960s, the field of computational linguistics became that sub-division of artificial intelligence dealing with human-level comprehension and production of natural languages. In order to translate one language into another, it was observed that one had to understand the grammar of both languages, including both morphology and syntax.
In order to understand syntax, one had to understand the semantics and the lexicon, something of the pragmatics of language use. Thus, what started as an effort to translate between languages evolved into an entire discipline devoted to understanding how to represent and process natural languages using computers. Nowadays research within the scope of computational linguistics is done at computational linguistics departments, computational linguistics laboratories, computer science departments, linguistics departments; some research in the field of computational linguistics aims to create working speech or text processing systems while others aim to create a system allowing human-machine interaction. Programs meant for human-machine communication are called conversational agents. Just as computational linguistics can be performed by experts in a variety of fields and through a wide assortment of departments, so too can the research fields broach a diverse range of topics; the following sections discuss some of the literature available across the entire field broken into four main area of discourse: developmental linguistics, structural linguistics, linguistic production, linguistic comprehension.
Language is a cognitive skill. This developmental process has been examined using a number of techniques, a computational approach is one of them. Human language development does provide some constraints which make it harder to apply a computational method to understanding it. For instance, during language acquisition, human children are only exposed to positive evidence; this means that during the linguistic development of an individual, only evidence for what is a correct form is provided, not evidence for what is not correct. This is insufficient information for a simple hypothesis testing procedure for information as complex as language, so provides certain boundaries for a computational approach to modeling language development and acquisition in an individual. Attempts have been made to model the developmental process of language acquisition in children from a computational angle, leading to both statistical grammars and connectionist models. Work in this realm has been proposed as a method to explain the evolution of language through history.
Using models, it has been shown that languages
In linguistics, morphology is the study of words, how they are formed, their relationship to other words in the same language. It analyzes the structure of words and parts of words, such as stems, root words and suffixes. Morphology looks at parts of speech and stress, the ways context can change a word's pronunciation and meaning. Morphology differs from morphological typology, the classification of languages based on their use of words, lexicology, the study of words and how they make up a language's vocabulary. While words, along with clitics, are accepted as being the smallest units of syntax, in most languages, if not all, many words can be related to other words by rules that collectively describe the grammar for that language. For example, English speakers recognize that the words dog and dogs are related, differentiated only by the plurality morpheme "-s", only found bound to noun phrases. Speakers of English, a fusional language, recognize these relations from their innate knowledge of English's rules of word formation.
They infer intuitively. By contrast, Classical Chinese has little morphology, using exclusively unbound morphemes and depending on word order to convey meaning; these are understood as grammars. The rules understood by a speaker reflect specific patterns or regularities in the way words are formed from smaller units in the language they are using, how those smaller units interact in speech. In this way, morphology is the branch of linguistics that studies patterns of word formation within and across languages and attempts to formulate rules that model the knowledge of the speakers of those languages. Phonological and orthographic modifications between a base word and its origin may be partial to literacy skills. Studies have indicated that the presence of modification in phonology and orthography makes morphologically complex words harder to understand and that the absence of modification between a base word and its origin makes morphologically complex words easier to understand. Morphologically complex words are easier to comprehend.
Polysynthetic languages, such as Chukchi, have words composed of many morphemes. The Chukchi word "təmeyŋəlevtpəγtərkən", for example, meaning "I have a fierce headache", is composed of eight morphemes t-ə-meyŋ-ə-levt-pəγt-ə-rkən that may be glossed; the morphology of such languages allows for each consonant and vowel to be understood as morphemes, while the grammar of the language indicates the usage and understanding of each morpheme. The discipline that deals with the sound changes occurring within morphemes is morphophonology; the history of morphological analysis dates back to the ancient Indian linguist Pāṇini, who formulated the 3,959 rules of Sanskrit morphology in the text Aṣṭādhyāyī by using a constituency grammar. The Greco-Roman grammatical tradition engaged in morphological analysis. Studies in Arabic morphology, conducted by Marāḥ al-arwāḥ and Aḥmad b. ‘alī Mas‘ūd, date back to at least 1200 CE. The linguistic term "morphology" was coined by August Schleicher in 1859; the term "word" has no well-defined meaning.
Instead, two related terms are used in morphology: word-form. A lexeme is a set of inflected word-forms, represented with the citation form in small capitals. For instance, the lexeme eat contains the word-forms eat, eats and ate. Eat and eats are thus considered. Eat and Eater, on the other hand, are different lexemes. Thus, there are three rather different notions of ‘word’. Here are examples from other languages of the failure of a single phonological word to coincide with a single morphological word form. In Latin, one way to express the concept of'NOUN-PHRASE1 and NOUN-PHRASE2' is to suffix'-que' to the second noun phrase: "apples oranges-and", as it were. An extreme level of this theoretical quandary posed by some phonological words is provided by the Kwak'wala language. In Kwak'wala, as in a great many other languages, meaning relations between nouns, including possession and "semantic case", are formulated by affixes instead of by independent "words"; the three-word English phrase, "with his club", where'with' identifies its dependent noun phrase as an instrument and'his' denotes a possession relation, would consist of two words or just one word in many languages.
Unlike most languages, Kwak'wala semantic affixes phonologically attach not to the lexeme they pertain to semantically, but to the preceding lexeme. Consider the following example:kwixʔid-i-da bəgwanəmai-χ-a q'asa-s-isi t'alwagwayu Morpheme by morpheme translation: kwixʔid-i-da = clubbed-PIVOT-DETERMINERbəgwanəma-χ-a = man-ACCUSATIVE-DETERMINERq'asa-s-is = otter-INSTRUMENTAL-3SG-POSSESSIVEt'alwagwayu = club"the man clubbed the otter with his club."That is, to the speaker of Kwak'wala, the sentence does not contain the "words"'him-the-otter' or'with-his-club' Instead, the markers -i-da, referring to "man", attaches not to the noun bəgwanəma but to the verb.
Phonology is a branch of linguistics concerned with the systematic organization of sounds in spoken languages and signs in sign languages. It used to be only the study of the systems of phonemes in spoken languages, but it may cover any linguistic analysis either at a level beneath the word or at all levels of language where sound or signs are structured to convey linguistic meaning. Sign languages have a phonological system equivalent to the system of sounds in spoken languages; the building blocks of signs are specifications for movement and handshape. The word'phonology' can refer to the phonological system of a given language; this is one of the fundamental systems which a language is considered to comprise, like its syntax and its vocabulary. Phonology is distinguished from phonetics. While phonetics concerns the physical production, acoustic transmission and perception of the sounds of speech, phonology describes the way sounds function within a given language or across languages to encode meaning.
For many linguists, phonetics belongs to descriptive linguistics, phonology to theoretical linguistics, although establishing the phonological system of a language is an application of theoretical principles to analysis of phonetic evidence. Note that this distinction was not always made before the development of the modern concept of the phoneme in the mid 20th century; some subfields of modern phonology have a crossover with phonetics in descriptive disciplines such as psycholinguistics and speech perception, resulting in specific areas like articulatory phonology or laboratory phonology. The word phonology comes from phōnḗ, "voice, sound," and the suffix - logy. Definitions of the term vary. Nikolai Trubetzkoy in Grundzüge der Phonologie defines phonology as "the study of sound pertaining to the system of language," as opposed to phonetics, "the study of sound pertaining to the act of speech". More Lass writes that phonology refers broadly to the subdiscipline of linguistics concerned with the sounds of language, while in more narrow terms, "phonology proper is concerned with the function and organization of sounds as linguistic items."
According to Clark et al. it means the systematic use of sound to encode meaning in any spoken human language, or the field of linguistics studying this use. Early evidence for a systematic study of the sounds in a language appears in the 4th century BCE Ashtadhyayi, a Sanskrit grammar composed by Pāṇini. In particular the Shiva Sutras, an auxiliary text to the Ashtadhyayi, introduces what may be considered a list of the phonemes of the Sanskrit language, with a notational system for them, used throughout the main text, which deals with matters of morphology and semantics; the study of phonology as it exists today is defined by the formative studies of the 19th-century Polish scholar Jan Baudouin de Courtenay, who shaped the modern usage of the term phoneme in a series of lectures in 1876-1877. The word phoneme had been coined a few years earlier in 1873 by the French linguist A. Dufriche-Desgenettes. In a paper read at the 24th of May meeting of the Société de Linguistique de Paris, Dufriche-Desgenettes proposed that phoneme serve as a one-word equivalent for the German Sprachlaut.
Baudouin de Courtenay's subsequent work, though unacknowledged, is considered to be the starting point of modern phonology. He worked on the theory of phonetic alternations, may have had an influence on the work of Saussure according to E. F. K. Koerner. An influential school of phonology in the interwar period was the Prague school. One of its leading members was Prince Nikolai Trubetzkoy, whose Grundzüge der Phonologie, published posthumously in 1939, is among the most important works in the field from this period. Directly influenced by Baudouin de Courtenay, Trubetzkoy is considered the founder of morphophonology, although this concept had been recognized by de Courtenay. Trubetzkoy developed the concept of the archiphoneme. Another important figure in the Prague school was Roman Jakobson, one of the most prominent linguists of the 20th century. In 1968 Noam Chomsky and Morris Halle published The Sound Pattern of English, the basis for generative phonology. In this view, phonological representations are sequences of segments made up of distinctive features.
These features were an expansion of earlier work by Roman Jakobson, Gunnar Fant, Morris Halle. The features describe aspects of articulation and perception, are from a universally fixed set, have the binary values + or −. There are at least two levels of representation: underlying representation and surface phonetic representation. Ordered phonological rules govern how underlying representation is transformed into the actual pronunciation. An important consequence of the influence SPE had on phonological theory was the downplaying of the syllable and the emphasis on segments. Furthermore, the generativists folded morphophonology into phonology, which both solved and created problems. Natural phonology is a theory based on the publications of its proponent David Stampe in 1969 and in 1979. In this view, phonology is based on a set of universal phonological p