情态动词反意疑问句

一般情况下是和普通反意疑问句一样,在情态动词上改,比如.

You can play piano, can't you?
He can't go to school today, can he?

但注意下列情况:

1 当陈述部分带有情态动词ought to时，反意疑问部分在英式英语中用ought to 形式，在美式英语中用should形式。例如：

You ought to see the new picture,shouldn't you?

Teachers ought to be honoured,oughtn't they?

2 当陈述部分带有情态动词used to时，反意疑问部分可以用used to形式，也可以用did形式。例如：

She used to live abroad,usedn't she?

There used to be a newsstand in the corner of the street,didn't there?

3 当陈述部分带有情态动词must时，反意疑问部分需视must的含义而定。

a.当must表示“命令或强制”时，反意疑问部分用mustn't。例如：

You must do it by yourself,mustn't you?

b.当must表示“有必要”时，反意疑问句用needn't，例如：

You must see him tonight,meedn't you?

c.当must表示“一定”或“想必”等推测意义时，反意疑问部分不用mustn't，而根据must后的动词形式而定。例如：

He must be crazy to do so,isn't he?

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