三、didn't need to do与needn't have done

1．didn't need to do sth.表示"过去没有必要做某事"。

I didn't need to go to the bank after all-Mary lent me the money.

我终究不必去银行了--玛丽借给我钱了。

2．needn't have done sth.表示"本没有必要做某事"。即事情已经做了，但现在看来没必要。

You needn't have worked that late last night.It was harmful to your health.

你昨晚不必工作到那么晚，那对你的身体没好处。

注意下面两句的区别：

He didn't need to worry.

他不必担心。(是否担心，我们不知道)

He needn't have worried.

他本不必担心。(不必做的事情已经做了)

即时跟踪　用所给动词的正确形式填空(必要时加情态动词need)

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

(2)I didn't need(need) to get up early this morning, so I stay in bed until 9 a．m.

(3)I need someone to help(help) me out of the problem.

(4)My clothes need washing/to be washed(wash)，but I have time only on Sunday.

(5)You needn't finish(finish) the work today.You can hand in it tomorrow.

完成句子

1．在来到新学校前我本不必担心，因为在新学校我的同班同学对我很友好。

I needn't have worried before I came to the new school, for my classmates here are very friendly to me.(2015·天津)

2．--我已经准备好了野餐要带的各种食物。

--你的意思是我们不必带食物了吗？

-I've prepared all kinds of food for the picnic.

-Do you mean we needn't bring anything with us？(2014·湖南)

3．我订购了一些披萨，因此当我们疲惫地回家后就没有必要担心做饭的事了。

I've ordered some pizza, so we needn't worry about cooking when we get home tired.(2014·重庆)

4．--你让索菲亚帮忙了吗？

--我不需要--我自己就能做得很好。