将原句改为 主语 + don’t / doesn’t / didn't + 动词原形. 其中do/does为助动词,是来帮助实义动词构成否定或疑问句的,但加了do/does后,其后面的动词必须用动词原形. 如:I have a question.→ I don't have a question. 而用do,does还是did,就是看句子的主语是否为第三人称单数和句子的时态问题了. 如果句子中还有情态动词(can,should.)则在情态动词后加not. 如:I can dance.→ I can not dance.