英语改成否定句是什么意思
英语中变成否定句有两类。
一,祈使句的肯定句变成否定句。
直接在动词原形前面加don't。例如:Go out. ->Don't go out.
二,陈述句变成否定句。
1、在am/is/are/was/were后+not。例如:He is old.->He is  not old.
2、在情态动词后+not。例如:He can swim.->He can not swim.
3、.在助动词动词后+not。例如:
I will go tomorrow.->I will not go tomorrow.
4、借助助动词,在其后+not。一般现在时态借助do/does,一般过去时态借助助动词did+not,借助does/did之后动词还原。动词是原形的借助do,动词+s的,借助does,过去式的,借助did.例如:I know.->I don't know. He knows.->He doesn't know. They knew.->They didn't know.
5、其他变化。some -> any ,some 合成词-> any 合成词,too 变either,  and 变or。