Inter-language switching, once the pariah of language learners, is now an eminently respectable part of both bilingual language performance and linguistic analysis. Switching involves the use of more than one language code or system in an utterance. Such inter-language switching is endemic, creative and popular in many of the Outer Circle communities like Singapore, Hong Kong, and Malaysia. In places like Singapore, it may routinely involve three languages or even more—in Singapore that means especially English, Chinese and Malay. Most studies of switching are concerned with the forms of languages. This can be phonological, as happens when we swap from authentic to foreign pronunciation. It can be morphological, for instance in the unstable realization of the plural in Asian Englishes in public signs. Such forms may well become either standard or fully accepted variants respectively in Macao and Malaysia. As things stand at present, however, this use (or not) of the plural is not standard, and constitutes switching or cross-code interference. Switching requires that both speakers share sufficient knowledge of two or more shared languages. It is also typically asymmetrical, in that one speaker will be more competent than the other, or that one speaker will make more accommodation than the other. This may involve the negotiation and choice of the language which the two speakers best share for communication, or it may involve the selection of language forms appropriate to the language level of both, and especially the weaker speaker. Switching is therefore a communicative strategy. It is often deliberate and strategic, as when a stronger speaker accommodates to a less competent interlocutor. But it can also be motivated by language gaps, when a speaker lacks command of language forms for a particular task of communication. And with really competent bilinguals switches can be part of competent, witty, expressive interpersonal communication, where the enjoyment and exploitation of language resources seem to emerge naturally, rapidly, and seamlessly in the flow of communication. Bilingual children do this with particular ease and unconscious grace. Switching is a natural part of finding appropriate expression for a message.