【肯定句变否定句】 肯定句改否定句例子

肯定句变否定句

1. 简单句中含有系动词be和情态动词时，变否定句时需在系动词be和情态动词后加not。如：

I am a teacher．→I am not a teacher．

He can help me．→He can"t help me．

2. 简单句中谓语动词为行为动词时，要根据时态选用do的相应形式，把肯定句变为否定句。如：

The little girl wants to go there．→The little girl doesn"t want to go there． He did his work yesterday．→ He didn"t do his work yesterday．

3．祈使句变否定句时，一般在句首加Don"t，但Let us或Let"s开头的祈使句在 Let us或 Let"s后加not即可。如：

Put them over there．→Don"t put them over there．

Let us go home．→Let us not go home．

4．主从复合句中，主句是I think，I believe等结构，变否定句时，形式上否定主句，实际上否定从句。如：

I don"t think chickens can swim ．我认为鸡不会游泳。

5．“had better ＋动词原形”，变否定句时为“had better not ＋动词原形”。如：

You"d better go to school．→ You"d better not go to school．

6．动词不定式变否定式时，常在不定式to前加not。如：

The teacher tells me to do it．→ The teacher tells me not to do it．

7．使役动词和感官动词（make，let，hear，see，watch等）后接省略to的不定式，此种不定式变否定句时只需在省略to的动词原形前加not。如： I saw her work．→I saw her not work．

8．特殊形式的否定句，有以下几种：

（1）肯定句含有every-的合成词时，变否定句时改为no-。如：

Everything is ready．→Nothing is ready．

（2）肯定句中含有always， usually和ever时，变否定句时改为never。如：

He is always late for school．→He is never late for school．

（3）肯定句含有many，much时，变否定句时分别改为few，little。如：

Many students know him．→Few students know him．

（4）肯定句中含有still时，变否定句时应改为no longer。如：

Tom is still in bed．→Tom is no longer in bed．

（5）肯定句含有both， both．．．and，all时，变否定句时应改为never，neither．．．nor，none。如：

Both of us are students．→Neither of us is a student．

（6）肯定句含有nearly， almost时，变否定句时应改为 hardly。如：

Lily nearly knows him ．→Lily hardly knows him ．

（7）肯定句含有“形容词＋ enough”时，变为否定句时应改为“too ＋形容词的反义词”。如：

He is short enough to reach it.→He is too tall to reach it．

9.肯定句变否定句时，某些形容词，不定代词，或副词等也会作相应的改变。例如：

1）. I can see some mountains far away.

→ I can’t see any mountains far away.(some 变成any)

2）. He has already have peakfast.

→ He hasn’t have peakfast yet.(already 变成yet)

3）. We can swim, too.

→ We can’t swim, either.(too变成either)

4）. Jim likes meat very much.

→ Jim doesn’t like meat at all. (very much变成 not at all) 5）He likes singing and dancing.

→He doesn‘t like singing or dancing.(and 变成 or) 10.not 和代词all, each, everyone, everybody,及副词both, quite, altogether, always等词连用时表示部分否定。

No all the students prefer maths. 并非所有的学生都喜欢数学。

It is not always sunny here. 这里并不总是阳光明媚。

The answer is not quite proper. 这个答案并不完全正确。