陈述部分肯定式+疑问部分否定式
当陈述部分含有否定意思的词是unhappy,dislike,unfriendly等含有否定词缀的派生词时,疑问部分要用否定形式.如：
He looks unhappy,doesn't he?他看上去不高兴,不是吗?
The girl dislikes history,doesn't she?这女孩不喜欢历史,不是吗?
当主句的主语为第二、三人称时,其后的简短问句则应与主句相一致（此时,否定只看主句,与从句无关...）.例如：
Your sister supposes she needs no help,doesn't she?
You thought they could have completed the project,didn't you?
They don't believe she's an engineer,do they?
She doesn't expect that we are coming so soon,does she?
但如果主句的时态是过去时等等,疑问句应和主句的人称时态保持一致.