3.對于用need的提問, 肯定回答用must, 否定回答用needn’t

　　　 　　a. Need I come? Yes, you must. / No, you needn’t.

2.need作情態(tài)動詞時, 多用于否定句及疑問句中, 不用于肯定句中

　　　 　　a. It is still early. You needn’t hurry. =You don’t need to hurry.

　　　 　　b. It is 11 o’clock. Need I go now? =Do I need to go now ?

1.need作實義動詞時, 注意以下用法:

①.need to do sth; ②.need sb to do sth; ③.need doing sth (主動形式表被動意義)

　　　 　　a. You need to remain in bed.

　　　 　　b. I need you to help me with the housework.

　　　 　　c. The garden needs watering.( =The garden needs to be watered.)

3.should / ought to的區(qū)別:

　 　should / ought to一般可以通用. should側(cè)重于說話人主觀上的看法, 有時含有勸告, 建議的口氣, 即 “按我的想法應(yīng)該如何”; 　ought to語氣更強, 強調(diào)“有責(zé)任, 有義務(wù)做某事”或者 “按道理應(yīng)該如何”

　　　 　　a. “I will start the work at once.”　　 “I think you should start at once.”

　　　 　　b. “I will start the work tomorrow.”　 “No. You ought to start at once.”

2.表示推測或推論, 可譯為“可能, 應(yīng)該是”

　　　　 a. He should be home by now, I think.

　　　　 b. He should have arrived in Nanjing by this time.

1.表示義務(wù), 責(zé)任, 可譯為“應(yīng)當(dāng)”

　　　　 a. We should complete the text in time.

　　　　 b. You should be so careless.

4.表示推測, 表示“大概, 也許”的意思

　　　　 a. That would be the pen you are looking for.那也許是你在找的筆吧

3.表示請求, 愿望, 語氣客氣, 委婉

　　　　 a. I would like some tea.

　　　　 b. Would you mind closing the door ?

　　　　 c. Would you tell me something about your trip ?

2.would do sth可以表示過去經(jīng)常發(fā)生的動作, 相當(dāng)于used to do sth

　　　　 a. When we were children we would go swimming every summer.

　　　　 b. On Sundays he would go fishing for hours when he lived in the countryside.

1.表示主觀意志和愿望, 即“愿意,想要”

　　　　 a. Come here whenever you would.

　　　　 b. He would not leave before he finished his work.