do具有多种词性和词义。构成疑问句和否定句。代替动词。用于加强语气。有做、干、进行、表现、的确等意思。

相关介绍：

do词性

do是用于一般现在时的助动词，did则是用于一般过去时的'助动词。done是do的过去分词。do还有实义动词（有实在意义的动词）的解释：做，干，等。口语中，do 的否定式通常用缩写形式。例如，do not 略作don't，did not 略作didn't。助动词无法与be动词、动词原形一同使用。

do的用法

1. do用于一般现在时

例句:I often do my homework in the evening.

2. does用于第三人称单数的一般现在时

例句:He does his lessons every day.

3. did用于一般过去时

例句:They did homework yesterday.

4. doing常用于现在进行时或者非谓语动词(暂时不提)

例句:He is doing his homework now.

5. done 常用于完成时，被动态或者非谓语动词(暂时不提)

例句:

He has done his homework.

He had done his homework before he went out.

His homework is done.

作为助动词，常用于疑问句和否定句。

1. 一般疑问句

例句:Do you like English?

2. 选择疑问句

例句:Does he go to school by bus or by bike?

3. 特殊疑问句

例句:How do you go to school?

4. 反义疑问句

例句:You like English, don't you?

5. 否定句

例句:I don't like English.

另外，也可以用于表示强调, 此时需要重读。

例句:He does need your help. (does重读，强调确实需要帮助)

还有，也可以代替其他的动词，使句子更简练。

例句:

Who cleaned the windows?

Tom did.