Nearly one in five Americans speaks a language other than English at home, the Census Bureau says, an increase of nearly 50 percent during the past decade. Most speak Spanish, followed by Chinese, with Russian rising fast.
Some 47 million Americans 5 and older used a language other than English in 2000, the bureau said. That translates into the nearly one in five, compared with roughly one in seven 10 years ago.
In Massachusetts, 18.7 percent of the state's nearly 6 million people 5 and older, speak a foreign language at home -- less than 1 percent higher than the national average of 17.9. There also were more people considered "linguistically isolated" because of limited English, a situation that some analysts say can prevent people from assimilating fully into American society and hinder activities like grocery shopping or communicating with police or fire officials.
The Spanish-speaking population rose by 62 percent over the period to 28.1 million; slightly more than half also reported speaking English "very well." The numbers are a further reflection of the surge in immigration since 1990. The influx helped make Hispanics the largest minority group, surpassing blacks.
http://www.boston.com/news/nation/washington/articles/2003/10/09/percentage_of_non_english_speaking_americans_surges/