The United States does not have an official language at the federal level, but the most commonly used language is English, which is the de facto national language. In addition, 32 U.S. states out of 50 and all five U.S. territories have declared English as an official language. The great majority of the U.S. population speaks only English at home. The remainder of the population speaks many other languages at home, most notably Spanish, according to the American Community Survey (ACS) of the U.S. Census Bureau; others include indigenous languages originally spoken by Native Americans, Alaska Natives, Native Hawaiians, and native populations in the U.S. unincorporated territories. Other languages were brought in by people from Europe, Africa, Asia, other parts of the Americas, and Oceania, including multiple dialects, creole languages, pidgin languages, and sign languages originating in what is now the United States. Interlingua, an international auxiliary language, was also created in the U.S.

Pennsylvania Dutch, sometimes referred to as Pennsylvania German, is a variation of Palatine German spoken by the Pennsylvania Dutch, including the Amish, Mennonites, Fancy Dutch, and other related groups in the United States and Canada. There are approximately 300,000 native speakers of Pennsylvania Dutch in the United States and Canada.