ABSTRACT According to Austin (1962), utterances may contain three levels of speech act: a locution, an illocution, and a perlocution. Based on Austin’s (1962) and Searle’s (1979) speech act theories, and Leech’s (2014) politeness principles, the objectives of the thesis are to explore intentionality and politeness of the imperative by comparing its form, meaning, prosody, function and distribution with those of the declarative and interrogative in Taiwan Sign Language (TSL) contexts, and to compare the imperative with the quoted imperative in direct speech, and with the reported imperative in indirect speech in TSL discourse. The imperative can be used for many functions in contexts. Its force can be mitigated by politeness strategies used in TSL. TSL signers may give reasons, apologize with the form SORRY, and express gratitude to the addressee with the verb THANK. The imperative for a request can begin with the adverb PLEASE and end with the question tag such as MAY or GOOD GOOD-NOT. The polite request can be accompanied by nonmanual markers such as gentle manners, graceful motions, slower speed, or the final lowering of the head and chin. Different linguistic forms such as imperatives, declaratives or interrogatives with different degrees of politeness will be used according to the speech situation and the horizontal or vertical distance. Moreover, the imperative can begin with the first person plural subject WE or the dual personal pronoun YOU-TWO. The former makes a suggestion that includes the signer. Further, the imperative can be negated by the auxiliary DON’T expressing prohibition and the modal MAY-NOT expressing absolute permission refused. In addition, the imperative can be quoted with the reporting verb such as SAID or TOLD in direct speech. The referential, spatial, temporal or affective shifts occur when the reporter assumes the role of the character from the spatial, affective and attitudinal perspective of the character in the quoted imperative. The point of view may change from the third person to the overt or implied second person, both of which are assigned to the same locus in direct speech. The reporter such as the signer, the addressee, or the other person can also report the imperative, pass on instructions, or interpret and report the direct speech with the reporting verb such as TOLD or REQUESTED in indirect speech. S/he reports the imperative from her/his spatial perspective. The affective shift occurs when s/he accompanies the reported imperative by the character’s affective features from the affective and attitudinal perspective of the character.