The Mysteries of Bilingualism. Francois Grosjean

high. This explains why its position is just below and to the left of La in the figure. She also knows a third language, Lc (German), but not very well, and she uses it rarely. Hence its position in the lower left of the grid. Lucia is clearly bilingual in English and French, on both factors, and like many others, she also has some knowledge of another language but rarely uses it. Note that in this type of presentation, the position of each language can be based either on self‐assessment ratings, as in this case, or on the results of more objective tests.

      Separate grids can be used for each of the bilingual’s four language skills (speaking, listening, writing, and reading) since it is often the case that amount of use and degree of proficiency can be quite different in these skills in the different languages. Thus, some bilinguals may have very good oral comprehension of a language but may not speak it very well; others may know how to read and write one of their languages but not the other(s), and so on. A few years after the grid approach was proposed, two other researchers, Luk and Bialystok (2013), provided statistical evidence that bilingual experience does indeed involve at least two dimensions, language use (they call it bilingual usage) and language proficiency, and that these dimensions are not mutually exclusive. These variables are the first building blocks of the description of the bilingual to which others need to be added, as we will now see.

      If one is interested in a bilingual’s language use, one will invariably be confronted with the functions of the person’s languages, that is which language is used, when, for what and with whom. More than half a century ago, Weinreich (1953) had already stated that many bilinguals are accustomed to discuss some topics in only one of their languages. Several years later, Mackey (1962) divided language functions into external functions (language use in various situations and domains) and internal functions (the non‐communicative uses of language such as counting, praying, dreaming, etc.). Clearly not all facets of life in bilinguals require the same language, nor do they demand both languages. Based on this, Grosjean (1997, 2016 ) proposed the Complementarity Principle, which he defined as follows:

      Bilinguals usually acquire and use their languages for different purposes, in different domains of life, with different people. Different aspects of life require different languages.

      The principle is discussed and illustrated in Chapter 8, so it suffices to say here that it has an impact on a number of variables, notably language proficiency. If a language is spoken in a reduced number of domains and with a limited number of people, then it will not be developed as much as a language used in more domains and with more people. In the latter case, there will be an increase in specific vocabularies, stylistic varieties, discursive and pragmatic rules, etc. It is precisely because the need and use of the languages are usually quite different that bilinguals do not develop equal and total proficiency in all their languages. This is also true for the different language skills, such as reading and writing.

      Language proficiency, language use, and functions of languages influence two other variables that are proposed when describing bilinguals. The first is language mode (Grosjean 2001), and the second is language dominance. Concerning language mode, which will be treated in more depth in Chapter 7, bilinguals have to ask themselves two questions when communicating with others: “Which language should be used?” and “Should the other language be brought in?” The answer to the first question leads to language choice, that is, choosing a base language for the exchange. As concerns the second question, bringing in or not the other language, if the answer is “no,” then the bilingual is in a monolingual mode. This is the mode when speaking to monolinguals, reading in a particular language, listening to just one language, etc. If, on the other hand, the answer is “yes,” as when the bilingual is speaking to another bilingual who shares his/her languages and who accepts to change base language from time to time and intermingle them (e.g., code-switch and borrow), then the bilingual is in a bilingual mode. Here, both languages are activated but the base language more so than the other language. Other examples of when the bilingual mode is required are listening to two bilinguals who are mixing languages, interpreting from one language to another, doing a study that requires the two languages, either overtly or covertly, and so on. In between these two endpoints of the continuum, bilinguals can find themselves in various intermediary modes, depending on the situation, the topic, the interlocutors, etc.

The other variable that is influenced by language proficiency, language use, and functions of languages, is language dominance. For a long time, researchers asked themselves whether dominance was based on just proficiency, or use, or both, or whether it depended on basic skills such as reading and writing a language, or even whether it concerned when the languages were acquired. Silva-Corvalán and Treffers-Daller (2016) studied dominance extensively and came to the conclusion that a dominant language is that in which a bilingual has attained an overall higher level of proficiency at a given age, and/or the language which s/he uses more frequently, and across a wider range of domains. As we see, all three factors are mentioned in their definition.

      A final factor that needs to be included when describing bilinguals at a particular point in time concerns biculturalism. Are the bilinguals being described also bicultural and, if so, what impact does it have on their bilingualism (Grosjean 2015). Chapter 10 is dedicated to biculturalism but it worth mentioning here that bilingualism and biculturalism are not automatically coextensive. You can find bilinguals who are not bicultural (e.g., those bilinguals who have lived in just one culture, such as many Dutch people), biculturals who are not bilingual (e.g., British people who have migrated to the United States), as well as people who are both bicultural and bilingual. Biculturals can be characterized in the following way: They take part, to varying degrees, in the life of two or more cultures; they adapt, in part at least, their attitudes, behaviors, values, languages, etc., to these cultures; and they combine and blend aspects of the cultures involved. Being bicultural has a real impact on language knowledge and language use in bilinguals. One example that comes to mind concerns concepts in the bilingual lexicon. So called translation equivalents, such as French “pain” and English “bread” may share the same concept in bilinguals who are not bicultural, but certainly not if they are bicultural. The same is true of French “café” and English “coffee.”

      Language History

      One can describe a bilingual at a particular point in time, as we have just seen, but one also needs to describe that person’s bilingualism over time. We need to know which languages were acquired and when, whether the cultural context was the same or different, what the pattern of proficiency and use was over the years, how much language separation or language intermingling took place, which language(s) went through restructuring under the influence of another language, and whether some languages became dormant or even entered attrition. In addition, we need to find out about the bilingual’s moments of language stability and moments of language change where a language may suddenly acquire new importance, as when a person immigrates. These transition periods, which can last several years, are important in order to understand the evolution of a person’s bilingualism.

      A crucial factor in language history is the age of acquisition of each language. We need to know whether the person acquired both languages simultaneously as an infant (something that is relatively rare; see Chapter 3), or whether one language was acquired first followed by another a few years later, or in adolescence, or even in adulthood. We also want to know about the context in which each language was acquired, such in the family, outside the home, in the classroom, etc. Information is also needed as to the age at which individual skills started to be acquired in each language (speaking, reading, etc.), how many years were spent in formal learning of a language, etc.

      The question of language dominance is also something to examine in a person’s language history. One should be careful not to assume that a first language or “mother tongue” is automatically the dominant language. People’s personal language history may show quite different bilingual configurations at different moments in time. Thus, Grosjean (2010) describes how his dominance has changed four times over a stretch of some