题目

4个简单英语句子的语法疑问.
一
Don't let the children stay up too late on weekends,will you?
Don't let the children eat a lot of sweets,shall we?
这组句子后面的附近疑问词为什么会不同?语法书说不是只有let's的时候才用shall 期待您的解答.
二
She had her hair cut the day before yesterday,didn't she?
You had your watch repaired yesterday,hadn't you?
这2个句子,看不出来结构上有什么不同.为什么它们的附近疑问部分,会不同呢?
Why are unit nouns especially useful when they are used to modify a mass noun?
请问这句话中的 unit nouns，以及 mass noun，

提问时间：2021-03-31

答案

(you) Don't let the children stay up too late on weekends,will you?
这句说话祈使的对象是you,所以用will you
（we） Don't let the children eat a lot of sweets,shall we?
祈使对象是we,包括说话人,所以用shall we
She had her hair cut the day before yesterday,didn't she?
You had your watch repaired yesterday,hadn't you?
结构一样,照理说第二个应该用didn't you 因为两句中的had都是have得一般过去式,反义疑问句应借助助动词did
unit nouns单位名词 mass noun物质名词
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