如何变否定句

1、如何变否定句一如果句子中有助动词am, is , are, was, were, will , shall , would , should , have /has /had（+动词过去分词）的时候，变否定句时直接在这些助动词的后面加not。Eg. He is a student.He is not a student .They will play football tomorrow.They will not play football tomorrow .Tom has been to Beijing . （been是 be的过去分词）Tom has not been to Beijin

2、g .二如果句子中有情态动词：can ,may ,must ,need的时候，变否定句时直接在这些情态动词的后面加notEg. She can sing . He can not sing.三如果句子中没有助动词am ,is , are, was, were, will ,shall ,would ,should ,have /has /had（+词过去分词）也没有情态动词：can ,may ,must ,need的时候，变否定句时，要借用助动词do ,does ,did, 然后在do ,does ,did后面加not1.如果谓语动词末尾加了字母s 或es的时候，要借用助动词does然后加no

3、t 。 最后将原来的谓语动词末尾的字母s或es去掉，还原成动词原形。即结构为：does not +动词原形。Eg. He goes to school every day.He does not go to school every day.2. 如果谓语动词是has+名词或代词的时候，要借用助动词does然后加not 。 最后将原来的谓语动词has还原成动词原形have 。即结构为：does not +动词原形。Eg. He has a pen. He does not have a pen .3. 如果谓语动词是have+名词或代词的时候，要借用助动词do然后加not，后面部分照着抄。即结

4、构为：do not +动词原形。Eg. They have many books.They do not have many books .4. 如果谓语动词末尾加了字母d 或 ed的时候，要借用助动词did然后加not 。 最后将原来谓语动词的字母d 或ed去掉，还原成动词原形，即结构为：did not +动词原形。Eg .I played basketball yesterday. You did not play basketball yesterday .5. 如果谓语动词是不规则动词过去式的时候，要借用助动词did然后加not 。 最后将原来的不规则谓语动词还原成动词原形，即结构为：did not +动词原形。Eg. They went swimming last week. （went 是go的过去式） They did not go swimming last week .6. .如果谓语动词末尾没有加字母s 或es 或 d 或 ed，也不是 has+名词或代词，也不是不规则动词过去式的时候，要借用助动词do然后加not，后面部分照着抄，即结构为：do not +动词原形。Eg.They often clean their classroom. They do not often clean their classroom.四祈使句