The Concise Encyclopedia of Applied Linguistics. Carol A. Chapelle

can be changed but not the comparative level of activation of the two languages. This takes place, for example, in a bilingual interaction when a bilingual switches over completely to the other language (which becomes the base language). In the example above, language B would become totally active and language A slightly less active. Similarly, there can be a change in the level of activation of the two languages without a change in base language, as in Figure 1. Thus, when referring to language mode, both aspects need to be mentioned. For example, a Spanish‐English bilingual speaking Spanish to a Spanish monolingual is in a “Spanish monolingual mode”; the same bilingual speaking English to another Spanish–English bilingual is in an “English bilingual mode,” and so on.

      Movement Along the Language‐Mode Continuum

      A number of factors will influence a bilingual's position on the continuum, and hence the activation level of the languages concerned. First, there are the participants involved, that is, their language proficiency, their relationship, their language‐mixing habits and attitudes toward language mixing, their mode of interaction, and so forth. For example, the mode will be monolingual if a bilingual is interacting with a monolingual family member. Second, the situation of the interaction will influence language mode, that is, the physical location, the presence of monolinguals, the decorum, and so on. Dewaele 2001, for example, found that the formality of the situation turned out to be a crucial factor in determining the position of the speaker on the language‐mode continuum. Third, the form and content of the message being uttered or listened to will have an impact on the mode. Thus, if the topic is usually covered in another language, and the interactant is known to be bilingual, the bilingual speaker will slip into a bilingual mode so as to call upon the other language for a word or an expression. In such cases, the base language may even change. Finally, the function of the language act (to communicate information, to request something, to create a social distance, to exclude someone, etc.) may change the language mode.

      Movement along the continuum can occur at any time when the above factors change. In addition, the movement is usually not conscious. Bilinguals will also differ among themselves as to the extent to which they travel along the continuum. Some are rarely at the bilingual end—they mainly communicate with monolinguals or remain within one language with bilinguals. Others, such as bilinguals who live in bilingual communities, rarely leave the bilingual end.

      Impact on Language Behavior

The particular language mode bilinguals are in will have an effect on the amount of use of the other (guest) language, the amount and type of mixed language used, the ease of processing of the two languages, and the frequency of base‐language change. For example, in the monolingual mode, the language not being used is deactivated. This prevents a change in base language and limits almost totally the use of code switches and borrowings. However, dynamic interferences—deviations from the language being spoken due to the influence of the other deactivated language(s)—may still take place. In the bilingual mode, bilinguals usually first adopt a base language through the process of language choice and, when needed, bring in the other—guest—language in the form of code switches and borrowings. In addition, the base language itself can be changed, that is, the slightly less activated language becomes the base language, and vice versa. A change of topic, of situation, of interlocutors, and so on, may lead to a change of base language. In perception, a monolingual mode will usually “block out” the other language, leading sometimes to misperceptions if the latter is used, or slower processing. Cheng and Howard 2008 examined the cost of language switching when it was unexpected in one context (monolingual mode) and expected in the other (bilingual mode). They showed a significant reaction‐time difference in the two conditions, thereby illustrating the impact of language mode during perception.

Evidence for Language Mode

      There is increasing evidence of the importance of language mode in bilingual communication. In language production, observational and experimental studies have shown its impact. Poplack 1981 showed that a member of El Barrio—a Puerto Rican neighborhood in New York—produced about four times more code switches in informal situations, compared to formal situations. Treffers‐Daller 1998 placed a Turkish–German bilingual in three different situations and showed changes in the base language used as well as differences in the amount of code switching that took place. In a series of experimental studies, Grosjean and his colleagues (reported in Grosjean, 2008) manipulated the language mode participants were in using a “telephone chain” task, and studied the impact this had on language production. The number of guest‐language elements (code switches, borrowings) increased significantly as the participants moved from a monolingual to a bilingual mode, whereas the number of base‐language syllables decreased, as did the number of hesitations.

      In perception, Elman, Diehl, and Buchwald 1977 carried out a categorical‐perception study with bilinguals in which they controlled for the base language and “pushed” bilin‐guals toward the monolingual end of the language‐mode continuum (they used naturally produced stimuli, filler words in the base language, as well as carrier sentences in either English or Spanish). They found a boundary shift, with ambiguous stimuli perceived significantly more as English or as Spanish depending on the language condition listeners were in. In this study, unlike in an earlier study by Caramazza, Yeni‐Komshian, Zurif, and Carbone 1973, there was constant language‐specific information which activated one language much more than the other and hence kept the bilinguals toward the monolingual end of the continuum.

      In language acquisition, there is increasing evidence of the importance of language mode. For example, Lanza 1992 studied a 2‐year‐old Norwegian–English bilingual child, Siri, interacting with her American mother who feigned the role of a monolingual and did not mix languages, and with her Norwegian father who accepted Siri's language mixing and responded to it. Siri did much more content‐word mixing with her father than with her mother, showing thereby that she leaned toward the monolingual end of the continuum with the latter and the bilingual end with the former. Genesee, Boivin, and Nicoladis 1996 recorded English‐French bilingual children as they spoke to their mother, to their father, and to a stranger who only spoke their weaker language. The more a parent switched languages during communication, the more the child did too. Thus, as in Lanza's study, children were more in a monolingual mode with parents who did not mix languages much, whereas they were more in a bilingual mode with parents who mixed languages to a greater extent (or accepted language mixing).

      In the domain of language pathology, Marty and Grosjean 1998 manipulated language mode in a study that examined spoken‐language production in eight French–German aphasic bilinguals. The latter were asked to carry out a certain number of language tasks by two different experimenters—the first was a totally monolingual French speaker who knew no German, and the second was a French–German bilingual. The patients knew about the experimenters' language background before testing. The authors found that two patients could no longer control their language mode due to their pathology but the six others adapted their language behavior to the experimenter, that is they did not mix their languages with the monolingual experimenter (or, if they did do so, it was due to stress or fatigue).

Language Mode in Different Groups of Bilinguals

      Studies of language mode have been carried out in relation to different groups of bilinguals. Four examples are given here.

      Highly Language‐Dominant Bilinguals

      It has been reported repeatedly that highly dominant bilinguals (e.g., members of a minority group who rarely use the majority language, bilingual children who are strongly dominant in one language, second language learners who use their new language, etc.) do more language mixing when speaking their weaker language than they do when using their stronger language (Lanza, 1992; Genesee, Nicoladis, & Paradis, 1995). They do not seem to be able to control language mode when speaking their weaker language in the way less dominant, or balanced, bilinguals can. They attempt to deactivate their stronger language in a monolingual environment