Emphasis has significant effect on F0 contours in various languages, among which tone languages require more careful study because their F0 contours show complex interaction between lexical tones and phrase intonation. Here we employ the command-response model to investigate the effect of paralinguistic emphasis in Cantonese, a typical tone language with nine lexical tones. Following our previous study on target syllables in a fixed carrier frame, the current study continues to investigate the utterances with natural context, in which the effects of emphasis with different scopes and on different parts of utterance are compared. It is shown that the major effect of emphasis is not on tone commands but on phrase commands. The narrowness/broadness of emphasis can be distinguished by the number of phrase commands being affected in the phonetic realization. By use of the command-response model, F0 contours for expressive speech conveying the information of emphasis can be generated efficiently.