What do we mean when we say ‘bilingual’?

The New York Times published an opinion piece this weekend titled, Are We Really Monolingual?. The piece mainly focuses on the various issues in how we try to estimate the number of languages a person speaks. The article writes,

Since 1980, the United States Census Bureau has asked: “Does this person speak a language other than English at home? What is this language? How well does this person speak English?” … This figure is often taken to indicate the number of bilingual speakers in the United States.

There are countless Americans who speak languages other than English outside their homes: not just those of us who have learned other languages in school or through living abroad, but also employers who have learned enough Spanish to speak to their employees; workers in hospitals, clinics, courts and retail stores who have picked up parts of another language to make their jobs easier; soldiers back from Iraq or Afghanistan with some competency in Arabic, Pashto or Dari; third-generation kids studying their heritage language in informal schools on weekends; spouses and partners picking up the language of a loved one’s family; enthusiasts learning languages with computer software like Rosetta Stone. None of the above are identified as bilingual by the Census Bureau’s question.

While the article ends on the note that we do not have clear statistics on the rates of multilingualism in the United States (or the world), this article actually gets at an important, deeper question of how we define bilingualism (or multilingualism). So what do we mean when we say that someone is bilingual? 

This not only is a question that needs to be addressed at a political and societal level, but also needs to be addressed in research. Let’s take a look at some of the terms we use when we talk about people who learn and speak two (or more) languages:


This is probably the most general of terms that are used when we talk about people who speak two languages. How we define bilingualism largely depends on the researcher and his/her research question, or the policy-maker and his/her legal policy. Some say that someone is bilingual if s/he speaks two languages–irrespective of his/her fluency in the languages. Others say that someone is bilingual only if s/he speaks the two languages fluently at a native-speaker’s proficiency (also referred to as a native bilingual). Others simply say that if the person speaks each of the two languages about 50% of the day, then s/he is bilingual; this definition is possibly the one most commonly used in developmental psychology research. Others differentiate between those who learned both languages from birth, at the same time (a simultaneous bilingual), and those who learned (or started learning) one language before the other during childhood (a sequential bilingual). And finally, others–especially those interested in language development and the learning process–focus on the timing of when a second language was acquired, by differentiating between early bilinguals (those who began learning a second language early in childhood) and late bilinguals (those who began learning a second language later in childhood and beyond). Where a researcher draws the line between an early and late bilingual, depends on the researcher and the research question, but it is generally around the age of 7 years.

Second Language Learner / Second Language Acquisition

The definition of a second language learner has some similarities with the definition of a sequential bilingual. A second language learner is someone who generally has learned (or is learning, if s/he is a child) his/her native first language and is learning another language. The term second language is generally used to refer to the second language that an individual learned/is learning and speaks non-natively, meaning without a native-speaker’s proficiency (e.g., a non-native speaker of English may have grammatical errors in their speech, such as saying “three furnitures” when it should be “three pieces of furniture”).

Foreign Language Learner

This is possibly the most specific of these three terms. The term foreign language learner usually refers to an individual who (1) has learned/is learning a language different from his/her native language(s) in a classroom environment (or other educational settings, such as through using programs like Rosetta Stone) and (2) uses this language for very specific purposes, such as travel or educational/vocational purposes. Some researchers differentiate between second language learners and foreign language learners because (1) the context in which an individual learns a language and (2) the role of that language in the individual’s life can produce differences in what is learned. For example, if a young adult learns a new language by surrounding him/herself with native speakers of that language (this process is referred to as immersion), then that individual would learn every-day words and phrases that are culturally-relevant (e.g., idioms, sayings, slang). If, on the other hand, a young adult learns a new language in an educational setting and/or to use at work, then that individual would learn a very specific set of words, phrases, and grammatical properties that may or may not parallel what the second language learner is learning in an immersion environment.

After reading these definitions, if you’re thinking that there are still pieces of the puzzle that are missing, you’re absolutely right. Some questions that might arise from reading this are, “What does she mean when she uses the term proficiency? What if someone can speak multiple languages completely grammatically, but has a really thick accent and thus has trouble communicating with others? How do we actually determine whether someone is bilingual or a second language learner?” Unfortunately, there may not be clear answers to these questions. To some degree, they all depend on how we define these terms for the purposes of our research question or legal policies at hand. However, these are the types of questions that are currently being addressed and examined by various researchers in linguistics, cognitive science, and psychology. So stay tuned! We still have much to learn about what we mean when we say bilingual.



Bergmann, A., Hall, K.C., & Ross, S.M. (Eds.). (2007). Language files: Materials for an introduction to language and linguistics (pp. 339-342). Columbus, OH: Department of Linguistics, The Ohio State University.

Parker, F., & Riley, K. (2005). Linguistics for Non-linguists: A primer with exercises (pp. 214-234). Boston, MA: Pearson Allyn and Bacon.

Wei, L., & Moyer, M. G. (2008). The Blackwell Guide to Research Methods in Bilingualism and Multilingualism. Malden, MA: Blackwell Publishing.