I don't think you need be so polite to her.

You don't have to work so hard if you just want to pass Band 4.

Because of the heavy rain, the children have had to get up earlier than usual this week.

2. need后面接动词的完成式，主要用于否定句，表示本可不必做某事。

"needn't　+不定式完成式"表示"本来不必做，但实际做了"。

注：didn't need to do表示： 过去不必做某事, 事实上也没做。

　　Needn't have done表示： 过去不必做某事, 但事实上做了。

John went to the station with the car to meet Mary, so she didn't need to walk back home.

John went to the station with the car to meet Mary, so she needn't have walked back home.

There was plenty of time. She __________.

A. mustn't have hurried B. couldn't have hurried　　

C. must not hurry D. needn't have hurried

答案D。needn't have done. 意为"本不必"，即已经做了某事，而时实际上不必要。

Mustn't have done 用法不正确，对过去发生的事情进行否定性推断应为couldn't have done, "不可能已经"。 must not do 不可以（用于一般现在时）。

Period four Learning about language

Step 1. Revision

1. Check the students' homework.

2. Ask some students to retell the text.

Step 2. Discovering useful words and expressions.

1. Find words and expressions from the text that mean the same.

1) ___________________something that you say is not true

2) ___________________not to be punished for something

3) ___________________uncooked

4) ___________________the strong wish to know about something

5) ___________________someone who buys things or services from a shop, company, etc

6) ___________________a particular quality that gives someone or something an advantage

2. Fill in the blanks with words from the left box and paraphrase the italicized parts using the phrases from the right box.