A1 如前所述，need not表示说话人的权威或劝告：

You needn't write me another cheque．Just change the date and initial¹ it．

你不必给我另开一张支票。你只需改一下日期并签上你姓名的第一个字母。

I'm in no hurry．He needn't send it by air．He can send it by sea．

我不着急。他不必用航空寄来。海运过来就行。

You needn't do it by hand．I'll lend you my machine．

你不必用手缝。我把缝纫机借给你。

You needn't call me Mr Jones．We all use first names here．

你不用管我叫琼斯先生。我们这里都只叫名字。

College lecturer：You needn't type your essays but you must write legi- bly．

大学教师：你们不必把文章用打字机打出来，但必须字迹清楚。

2 其他表示外界权威的形式：

Tom doesn't have to wear uniform at school．

汤姆在学校不一定要穿校服。

We don't have to type our essays but we have to write legibly．

我们的文章不一定要打出来，但字迹一定要清楚。

When I'm an old age pensioner² I won't have to pay any more bus fares．

等我到领取养老金的时候，我坐公共汽车就不用买票了。

Ann hasn't got to go／doesn't have to go to this lecture．Attendance³ is op- tional．

安不一定非去听讲。那讲座是可去可不去的。

When I have a telephone of my own I won't have to waste time waiting outside these wretched⁴ telephone boxes．

等我自己有了电话，我就不用等在讨厌的电话亭外而浪费时间了。

Ann doesn't have to cook for herself．She works at a hotel and gets all hermeals there．

安不用自己做饭吃。她在一家饭店工作，在那里用餐。

3 然而，有时need not也可以用于表示外界权威，以代替won't／ don't need to或won't／don't have to等各种形式。这种用法尤其普遍地用于第一人称：

I needn't／won't／don't have to type this report today．Mr Jones said that there was no hurry about it．

我今天不必把这个报告打出来。琼斯先生说这份报告不急着要。

请注意，虽然 need not可用来表示将来的习惯性动作：

I'm retiring．After Friday I need never go to the office again．

我就要退休了。星期五之后我就再也不必到办公室去了。

但不能用 need not表示一个现在的习惯性动作：

I don't have to queue for my bus．I get on at the terminus．

我用不着排队等公共汽车。我在首发站上车。（这里不能用need

not。）

B 过去时

如need用于过去时，说话人的权威和外界权威之间的差别就消失了，因而我们可任意运用以下三种形式：didn't have to，didn't need to和hadn't got to。这几种用法不存在含义上的差别，但 hadn't got to不常用于表示习惯性动作。 didn't have to 是最常用的：

I didn't have to wait long．He was only a few minutes late．

我没等太长时间。他只迟到了几分钟。

When he was at university he didn't have to／need to pay anything for his keep，for he stayed with his uncle．

他读大学时不需要付食宿费用，因为他与他的叔父住在一起。