如何变否定句.doc

如何变否定句
贵州省贞丰中学 安平
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 Beijing .
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not
Eg. 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not
1.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not 。 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．祈使句变否定句直接在动词原形的前面加don’t. ( 以动词原形开头的句子叫祈使句。)
Eg. Open the door.→
→ Don’t open the door.