陈述句改否定句其实就是在助动词或情态动词后面加not This dog is not(isn't) thinner than that one. Mike does not(doesn't) run faster than some of the boys in his class. It was not (wasn't) Sports Day at school.
This dog isn't thinner than that one. Mike doesn't run faster than any of the boys in his class. It wasn't Sports Day at school 被动词+not 成否定句 助动词否定式+行为动词 成否定句