其形式为助动词（包括情态动词）+not +主动词，若谓语动词为be，其否定式为be+not。
这类否定动词有：
①can not/can't②will not/won't③do not/don't④should not/shouldn'tYou should not read such a book.你不应该读这样的书。
⑤is not/isn'tHe is not a doctor.他不是医生。
⑥does not/doesn'tWood does not work very hard at school.伍德在学校学习不努力。
