Abstract: The tone of speaking has a function of speech act. Inquiring is an important tone and its basic function is “acquiring information”. Inquiring is not only related to a declarative act of “giving information”, but also related to an imperative act, which is act-demanding, and a promising act, which is act-giving. Then, how can we identify a certain speech act as inquiring? Besides the acceptable formal marks such as interrogative intonation, pronouns, patterns, and modal particles, there are other recognition parameters of the inquiring act: interrogative auxiliary word, single-noun sentence, incomplete sentence, contextual position, especially “punctuation” and the structure of adjacent pair.