English is the business language in almost all businesses in the United States.

Many Americans speak only English. Spanish is another common language due to the United States' proximity to Mexico and Central America and the large population of Spanish-speaking individuals in the country. However, English will still be used almost 100% for business deals.

Since most Americans speak only English, they may not be sensitive to the difficulties of other individuals trying to speak English. They may speak fast or very loudly [as if this will help you understand them better].

American business language is also very idiomatic. Many Americans adopt sports terms in their business speech ["Touch base," "Ballpark figures," "Call the shots," "Team players," and "Game plan" are a few examples.] Many Americans may not be aware that they are using these idioms because they seem so natural.

If language becomes a barrier, ask for clarification and seek understanding. If you are not totally comfortable speaking and doing business in English, hire a translator.