Tom doesn't have tennis racket,but his sister has one 为什么前面用have 后面要用has
问题描述：
Tom doesn't have tennis racket,but his sister has one 为什么前面用have 后面要用has
答
助动词后接动词原形，后面是第三人称单数形式
答
- - doesn't 已经单数了阿 have 怎么再单数
答
主语为单数如Tom , his sister 谓语都要用第三人称单数,所以后面的为has, 但是前面为否定,由助动词doesn't 加动词原形,所以用have.