Code-switching 1. Linguistic manifestations of language contact 5 Code-switching (CS) is but one of a number of the linguistic manifestations of language contact and mixing, which variously include borrowing on the lexical and syntactic levels, language transfer, linguistic convergence, interference, language attrition, language death, pidginization and creolization, among others. There is little consensus in the literature over which aspects should be subsumed under the label codeswitching. In this article, CS refers to the utterance-internal juxtaposition, in unintegrated form, of overt linguistic elements from two or more languages, with no necessary change of interlocutor or topic. Mixing may take place at any level of linguistic structure, and a long research tradition has grown up around questions of language choice and language negotiation among interlocutors in bilingual contexts (Gumperz 1976/1982; Heller 1982). But the combination of languages within the confines of a single sentence, constituent or even word, has proved most intriguing to linguists. This article surveys the treatment in the literature, linguistic and social, of such intra-sentential CS. 2. Theories of CS First dismissed as random and deviant (e.g., Weinreich 1953/1968); intra-sentential CS is now known to be grammatically constrained. The basis for this is the empirical observation that bilinguals tend to switch intra-sententially at certain (morpho)syntactic boundaries and not at others. Early efforts to describe these tendencies (e.g., Gumperz 1976/1982; Timm 1975) offered taxonomies of sites in the sentence where CS could and could not occur (e.g., between pronominal subjects and verbs or between conjunctions and their conjuncts), but these were soon met with a host of counter-examples.
Poplack, Shana. 2004. Code-switching. Soziolinguistik. An international handbook of the science of language, 2nd edition, ed. by U. Ammon, N. Dittmar, K.J, Mattheier & P. Trudgill. Berlin: Walter de Gruyter.
The first general account of the distribution of CS stemmed from the observation that CS is favored at the kinds of syntactic boundaries which occur in both languages. The Equivalence Constraint (Poplack 1980) states that switched sentences are made up of concatenated fragments of alternating languages, each of which is grammatical in the language of its provenance (see also Lipski 1978; Muysken 2000; Pfaff 1979). The boundary between adjacent fragments occurs between two constituents that are ordered in the same way in both languages, ensuring the linear coherence of sentence structure without omitting or duplicating lexical content. That general principles, rather than atomistic constraints, govern CS is now widely accepted, though there is little consensus as to what they are or how they should be represented. Many theories assume that the mechanisms for language switching are directly predictable from general principles of (monolingual) grammar. As extensions of the formal linguistic theories successively in vogue, these tend to appeal to such abstract grammatical properties as interconstituent relationships (e.g., government, case assignment) and/or language-specific features of lexical categories (i.e., subcategorization of grammatical arguments, inherent morphological features). Di Sciullo, et al. (1986), for example, identified the relevant relations as C-command and government: CS cannot occur where a government relation holds. Replacement of the function of government in standard theory by the notion of feature agreement led to a parallel focus on feature matching in CS studies. The Functional Head Constraint (Belazi, et al. 1994)...