American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the U.S., as well as the common language used in government, education, and commerce in all 50 states, the District of Columbia, and in all U.S. territories except Puerto Rico. Since the late 20th century, American English has become the most influential form of English worldwide.