do詞性

　　do是用于一般現(xiàn)在時的助動詞，did則是用于一般過去時的助動詞。done是do的過去分詞。do還有實義動詞（有實在意義的動詞）的解釋：做，干，等。口語中，do 的否定式通常用縮寫形式。例如，do not 略作don't，did not 略作didn't。助動詞無法與be動詞、動詞原形一同使用。

　　do的用法

　　1. do用于一般現(xiàn)在時

　　例句:I often do my homework in the evening.

　　2. does用于第三人稱單數(shù)的一般現(xiàn)在時

　　例句:He does his lessons every day.

　　3. did用于一般過去時

　　例句:They did homework yesterday.

　　4. doing常用于現(xiàn)在進行時或者非謂語動詞(暫時不提)

　　例句:He is doing his homework now.

　　5. done 常用于完成時，被動態(tài)或者非謂語動詞(暫時不提)

　　例句:

　　He has done his homework.

　　He had done his homework before he went out.

　　His homework is done.

　　作為助動詞，常用于疑問句和否定句。

　　1. 一般疑問句

　　例句:Do you like English?

　　2. 選擇疑問句

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

　　3. 特殊疑問句

　　例句:How do you go to school?

　　4. 反義疑問句

　　例句:You like English, don't you?

　　5. 否定句

　　例句:I don't like English.

　　另外，也可以用于表示強調(diào), 此時需要重讀。

　　例句:He does need your help. (does重讀，強調(diào)確實需要幫助)

　　還有，也可以代替其他的動詞，使句子更簡練。

　　例句:

　　Who cleaned the windows?

　　Tom did.