Almost 1 million people immigrate to the United States every year, although the Census Bureau predicts that the number will drop to about 700,000 a year by 2011.
The main reason people come to the United States is for better-paying jobs.
For example, one study noted that people who were earning about $31 a week in Mexico could make $278 a week in the United States.
More than 30 million Americans are non-native speakers of English.
Spanish-speaking people lead the list, followed by native speakers of French, German, Italian, Chinese, Tagalog, Polish, Korean, and Vietnamese.