Previous studies on the Cantonese mai have mostly been focused on its negation function, treating maias a negative adverb. In fact, Cantonese has another mai that has not received much attention in the past, and that is the adverb mai6. Differing in the tone, this adverb mai6 has no direct relation with the negative adverb mai5 and is rather used subjectively to express the speaker's subjective emotions and attitude. For example, mai6 has a sense of casualty or unimportance, or even impatience. This paper explores the discourse-pragmatic functions of mai6 and the motivations for it to develop into a subjective marker.