Bilinguals often switch between their two languages or language varieties in the middle of a conversation. This phenomenon is called code-switching. It can take place between or even within sentences, involving phrases or words, or even part of words. A speaker does not necessarily have to follow a particular variety or dialect all the time in the course of communication. He may change from a standard dialect to a nonstandard dialect; he may shift to a subject which requires the occurrence of some special items; he may move from one degree of formality to another. All these linguistic behaviors belong to code switching. There are two kinds of code-switching: situational code-switching and metaphorical code-switching. Situational code-switching occurs when the language used changes according to the situation in which the participants find themselves; they speak one language in one situation and another in a different one. No topic change is involved. When a change in topic requires a change in the language used we have metaphorical code-switching. It has been found speakers bilingual in Swahili and English would use Swahili when talking about education and English when talking about prejudice. The interesting point here is that some topics may be discussed in either code, but the choice of code adds a distinct flavor to what is said about the topic. The choice itself encodes certain social values.