在主语后动词前加DON‘T, DOESN’T （一般现在时第三人称单数）,DIDN‘T（ 一般过去时） ,原来的动词要用回原形.如
He works hard .->He doesn't work hard.
We study English.- > We don't study English.
He went to Beijing last year. -> He didn't go to Beijing last year.