不知道后面的疑问句该否定还是肯定,不知道主语用什么,

反义疑问句分两种：前肯定后否定、前否定后肯定.疑问句用否定还是肯定,取决于前面一句的意思,因为有的句子没有明显的not提示,而使用seldom等否定词来否定句子的意思.所以遇到这种问题时,若前面句意是肯定的,后面就否定,前面否定后面就肯定.
请注意以下句型的反义疑问句的用法：
1．当陈述部分的主语是I ,everyone,everything,nobody 时,后面的疑问句应表示为：
I am a student,aren’t I
Everyone is in the classroom,aren’t they?
Everything begins to grow in spring,doesn’t it?
Nobody will go,will they?
2.当陈述部分有never,seldom,hardly,few,little,barely,scarcely,nothing 等否定词时,后面的疑问句则表示为：
There are few apples in the basket,are there?
He can hardly swim,can he?
They seldom come late,do they?
3.当陈述部分是I think 加从句时,疑问句应和从句的人称时态保持一致.
I think chickens can swim,can’t they?
I think Lucy is a good girl,isn’t she?
I didn't think he was happy,was he?
4.陈述部分有had better 时,疑问句应用hadn’t开头：
you’d better get up early,hadn’t you?
5.当陈述部分是祈使句时,疑问句要根据语气来表达
Let’s go out for a walk,shall we?
Let us go our for a walk,will you?
Turn on the radio,will you?
6.反义疑问句的回答用yes,no,但是,当陈述部分是否定形式时,回答要按事实.如：
They don’t work hard,do they?他们不太努力工作,是吗?
Yes,they do.不,他们工作努力./No,they don’t.对,他们工作不努力.

反义疑问句始终遵循“前肯后否，前否后肯”原则

如果疑问句是肯定,附加部分用否定;如果疑问句是否定,附加部分用肯定。主语要保持一致。