* Defining "foreign language" is subjective: Some consider languages like Spanish or French to be "foreign," while others might include less common languages like Tagalog or Mandarin.
* Data collection is complex: Surveys often rely on self-reporting, which can be inaccurate. Also, the definition of "speaking" a language can vary – does it mean being fluent, conversational, or simply understanding some basic phrases?
* Language use changes: People's fluency levels change over time, and the prevalence of certain languages shifts.
However, we can look at some estimates:
* The U.S. Census Bureau: Their 2021 American Community Survey estimated that about 25% of the U.S. population over the age of 5 speaks a language other than English at home. This translates to approximately 82 million people.
* Modern Language Association (MLA): They estimate that around 55% of Americans speak a language other than English, though they include people who may have limited proficiency.
* Other studies: Various studies have shown that the number of people who speak a language other than English at home has been steadily increasing in recent decades.
To summarize: While exact figures are hard to pin down, estimates suggest that a significant portion of the U.S. population speaks a language other than English. The actual number depends on how you define "foreign language" and "speaking" a language.