1. Code-Switching
The particular dialect or language that a person chooses to use on any occasion is a code, a system used for communication between two or more parties.
It is unusual for a speaker to have command of, or use, only one such code or system.

2. Most speakers command several varieties of any language they speak, and bilingualism, even multilingualism, is the norm for many people throughout the world rather than unilingualism.

3. Speakers of more than one language are known for their ability to code switch or mix their language during their communication.
People switch code within a domain or social situation.
The switch will be clear, when there is an obvious change in the situation.

4. A speaker may similarly switch to another language as a signal of group membership and shared ethnicity with an addressee.

5. Situational switching refers to the tendency in a bilingual or multilingual community to use different languages or language varieties in different social situations. It may be based on the topic, on the addressee, the institution, or on any specific combination of situational factors.

6. Code-switching (also called code-mixing) can occur in conversation between speakers’ turns or within a single speaker’s turn. In the latter case it can occur between sentences (intersententially) or within a single sentence (intra-sententially).
Code-switching can arise from individual choice or be used as a major identity marker for a group of speakers who must deal with more than one language in their common pursuits.

7. ‘codeswitching is a conversational strategy used to establish, cross or destroy group boundaries; to create, evoke or change interpersonal relations with their rights and obligations.

8. The functions and reasons of Code Switching
① To show identity with a group to stress the fact that they all belong to this group
② Lack of Facility: switch when they cannot find an appropriate expression or vocabulary item .
③ Lack of Register: When speakers are not equally competent in two languages .
④ To attract attention: shows that code switching is used to attract the attention of the readers/listeners.

9. ⑤ language switch from L to H can signal disapproval
⑤ language switch from L to H can signal disapproval . We switch to express anger using different styles of English ⑥ used for amusement and dramatic a fact by telling joke for expressing emotions.