The primary, although not official, language of the United States is English. According to the 2000 U.S. Census, more than 97% of Americans can speak English well, and for 81% of the population, it is the only language spoken at home.

Other languages that are considered to be important to U.S. culture include:

• Spanish because of the proximity of and immigration from Mexico and other Spanish-speaking countries of the Caribbean and Central and South America, as well as the cultural crossover of the borderlands,
• the native Hawaiian language, and other native languages with large numbers of speakers (like Navajo)
• Korean, Chinese, Vietnamese, and Tagalog (Filipino dialect) due to immigration from the countries where those languages are spoken, and
• French, in Louisiana (a former French colony, where Cajun French is spoken), and in northern New England, home to many French Canadian immigrants in the past and which is also influenced by neighboring Acadian-Canadian culture.

There are more than 300 languages besides English which can claim native speakers in the United States--some of which are spoken by the indigenous peoples (about 150 living languages) and others which were imported by immigrants. Creoles native to the United States include Gullah and Cajun, both spoken in the Southeast. American Sign Language, used mainly by the deaf, is also native to the country.

There are four major regional dialects in the United States--northeastern, south, inland north and midlands. The Midlands accent (considered the "standard accent" in the United States, and analogous in some respects to the received pronunciation elsewhere in the English-speaking world) extends from what were once the "Middle Colonies" across the Midwest to the Pacific states.