“How can you tell?”

Rational Choice (RC) models of code-switching argue that bilingual speakers make rational choices according to the rights and obligations they perceive in a given situation. Some situations are marked and some unmarked. Speakers choose their languages to index their rational decisions, as well as their attitudes and identities. The Conversation Analysis (CA) approach to code-switching agrees with the RC model that bilingual speakers are rational individuals. But instead of being oriented to rights and obligations, or attitudes and identities, bilingual speakers are first and foremost assumed to be oriented to conversational structures aiming primarily at achieving coherence in the interactional task at hand. Their language choice and code-switching is therefore 'programmatically relevant' to the talk-in-interaction. The CA approach therefore begins where the RC model stops and seeks evidence from talk-in-interaction rather than from external knowledge of community structure and relations. Examples of conversational code-switching by Chinese-English bilinguals will be cited to support the arguments.