Modern chinese common imperatives＂A＋V＋（yi） dianr!＂（V representative of monosyllabic verb, A representative of monosyllabic adjective） indicates the speaker＇s attitude and willingness. In this sentence, A constantly is a semantic category of number of the adjective“duo”or“shao”. Other semantic category, however, can only construct as“V＋A＋（yi） dianr!”, which appears to be an unbalanced linguistic phenomenon. And the former format can be transformed to the later format, while the later usually cannot be transformed to the former. We explored the motivation and mechanisms of this construction from the grammarize of Chinese and the cognitive linguistics perspective. A result can be found that the sematic category of number which express“more”or“less”have a highly frequency of use in the imperative sentence which is context-dependent. Therefore,“A＋V＋（yi）dianr”is an unmarked construction which reserved the ancient Chinese construction as the adjective use before the verb.