英语肯定句变否定句的基本方法

【导语】英语语法让很多学生都头疼，因为复杂难懂的句式和词组有时难以记忆。本章主要介绍英语语法中的句子成分，希望对同学们的英语语法学习有所帮助。

1. be动词的否定式

be 动词根据不同的'人称和时态有不同的形式，在一般现在时中是am , is , are可用作联系动词，构成否定式时，一律在其后面加否定词not.

He is reading. --- He is not reading. They are from China. --- They are not from China.

2. 情态动词的否定式

情态动词的否定式是在其后面直接加not. 如：

I can swim. --- I cant swim. He can dance. --- He cant dance. You should go to school at seven. --- You shouldnt go to school at seven.

3. 实义动词的否定句

实义动词变否定句时，要借助助动词do , does，在一般现在时中用do或者does其句子结构为：主语+ dont / doesnt + 动词原形+其它 例如：

I like pop music. --- I dont like pop music. He likes running. --- He doesnt like running.

She does her homework at home. --- She doesnt do her homework at home