This paper aims to clarify some characteristics of Cp (constant polarity) tag sentences compared with Rp (reversed polarity) ones, in relation both to preceding utterances and following responses. Cp tag sentences are classified into two types in terms of what the RC (reference clause, on which a tag question is formed) states.<BR>In A type, the speaker of a Cp tag sentence echoes the whole or some part of the preceding utterance in the RC to which a Cp tag is added. He expresses his opinion of this preceding utterance and asks for the hearer's confirmation. Thus the RC is said to be explicitly stated in the preceding utterance. In B type, the speaker interprets the preceding utterance and also the preceding speaker's behavior, and anticipates his next utterance. The RC is the supposed part of the hearer's utterance, not the repetition of the explicit statement in the preceding utterance as in A. This B type is also used when the speaker is describing the situation or the event involving both the speaker and the hearer, by bringing the hearer to commit himself on it. In this case, the RC is the supposed appropriate description of the situation.<BR>RCs of both A and B types are expressions of the metalanguage, used for describing other words-words in the preceding utterance, the supposed part of the hearer's next utterance or the supposed description of the situation.<BR>Cp tag sentences are used basically for stating the speaker's reflection of the RC and asking for the hearer's confirmation, and also denoting the speaker's strong feeling that he hopes that the hearer admits ‘not RC.’