初一英语怎样句式变换

1．肯定句变否定句

肯定句变否定句一般由否定词not来否定句中谓语。初一竞赛范围涉及be动词（is，am，are），情态动词can，部分实义动词（不包括第三人称单数）等。

（1）凡是含有be（is，am，are），can的句子，变否定句时，一律在is， am，are，can后加not，即：am not，is not，are not，cannot（cannot一般不分开写）。除am not不可以用缩写式外，其它均可用缩写式，即：isn't， aren't，can't。如：

This is a car．→This is not（isn't）a car．

Those are birds．→Those are not（aren't）birds．

I am a student．→I am not a student．

We are Young Pioneers．→We are not（aren't）Young Pioneers．

She is my friend．→She is not（isn't）my friend．

There is a clock on the table．→There is not（isn't）a clock on the table．

I can see the boat on the river．→I can't see the boat on the river．

（2）祈使句的否定式一般是在祈使句前加don't。如：

Do it like that！→Don't do it like that！

Put on that coat．→Don't put on that coat．

（3）实义动词（不含第三人称单数）的否定式，是在实义动词前加don't构成。如：

I know it．→I don't k