什麼時候用does

歸納起來, do ,does 的用法有四方面：

一、用作一般的動詞，均可。do是一不規則變化的動詞(do ,did,done)。

do，據人稱和單複數的不同而有字形的變化。第一第二人稱，以及第一、二、三人稱的複數時，都用 do。

第三人稱單數時，用 does( he does  she does    it does )

例如: I do my homework on Sunday.

You do your homework on Sunday.

We do our homework on Sunday.

You do your homework on Sunday.

They do their homeworkon Sunday.

He does his homework on Sunday.

She does her homework on Sunday.

二.當助動詞用，用它來構成疑問句.這時它本身沒有實義，只是一個構成疑問句的符號而已.這種用法時，它隨人稱和數的變化規則與上述相同，只是把它放到句子的最前面(句首)。例如：

Do I ...............?

Do you .............?

Do we ..............?

Do you .............?

Do they ............?

Does he ............?

Does she ...........?

Does it ............?

三.當助動詞用，與 not 連用使句子構成否定句。其隨人稱和數的變化規則與上述相同。例如：

I do not ..................? (do not 可簡化為 don't ,下同)

You do not ................?

We do not..................?

You do not.................?

They do not................?

He does not................?  (does 可簡化為 doesn't,下同)

She does not...............?

四.當作助動詞,本身在句子中無實義，只是加強句子中動詞的語氣，其隨人稱和數的變化同上。例如：

Do write to me.(一定寫信給我!)

Never do I see such a fool.(我從來沒見過這樣的蠢才.)

She does come.(她的確來了.)

按詞性，do 還可以用作名詞。其意是"欺騙";"宴會,宴請"。例如：

It's all a do.(完全是欺騙.)

We have got a do on to-night.(家裏今晚請客.)