■ need

1) 这个动词（属第一类动词），可以是普通的实义动词，也可以是个助动词（否定或疑问时不用加 do，后面接上 inf. 不要 to）。但是它只有在否定句或疑问句中（而且后面的宾语不是名词而是动词不定式）才可以用作助动词，在肯定句中就要作为实义动词来处理。

• You needn't come if you don't want to.你不想来就不必来。
• She need never know.她根本不需要知道。
• Need you be so rude?有必要这样粗野吗？
• That needn't always be the case.不必总是如此。
• Need one remind her (= US State Secretary Condolezza Rice) of the torture skills some (US) soldiers brazenly demonstrated in the past? (Bahrein Tribune, May 19, 2005)一些大兵昔日大肆表演的拷打技巧，难道还要人家给她提醒吗？

2) 如果是肯定句，或者虽然是否定句或疑问句但宾语是名词（包括动名词）而非动词不定式，need 就仍然要作为普通的实义动词。

• I need to go to the post office.我需要到邮局去一趟。
• Do you need the hammer?你要用这锤子吗？
• Just what I needed!我正是得其所哉！
• I need someone to look after the children.我需要有人来看孩子。
• She didn't need telling twice.给她一说就通。

3) need 作为助动词，意义主要是指当前有或是没有某个必要（尤其是用来要求或允许当前免做某事），不指长远的需要。

• It's OK. You needn't pay for that phone call.行。那次打的电话你不用付钱了。
• I'm in no hurry. He needn't send it by air.我不急着要用。他不必寄航空。

这里的助动词 needn't，也可以改用普通动词 don't need to。但是如果讲的是长远的不需要，就只能用 don't need to。

• You don't need to (*needn't) pay for emergency calls in most countries.在大多数国家，拨紧急呼救电话时不用缴费的。
• I don't need to (*I needn't) queue for my bus. I get on at the terminus.我是在总站上公共汽车的，不需要排队。

4) 如果谈的是一段时间以后的需要，或是取决于另一事态的需要，need（普通实义动词）可以用一般将来时。

• We'll need to repair the roof next year.咱们明年要修理屋顶了。
• You'll need to fill out these forms before you see the immigration officer.你去见移民官员之前，要先填好这些表格。

5) need（用现在时）not have + pp 表示过去已经做了的某事现在看来本来是不必做的。

• You needn't have woken me up. I don't have to go to work today.你本来用不着把我喊醒。我今天不需要上班。
• I needn't have cooked so much food. Nobody was hungry.我本来不必做这么多的饭菜。谁也不饿。

但是，didn't need to 意思就有些不同，是就过去谈过去的背景情况，说当时不需要如何，但是实际上可能做了，也可能没有做（通常是没有做，但这只是从情理来推测，字面上并不交代）。

• It started raining, so I didn't need to water the flowers.下起雨来，所以我就不需要浇花了。

但是后面马上接着可以说：

• But I did water them in case it didn't rain enough.但是我还是浇了，以防万一雨水不够（从后一句看出“我”还是浇花了）。
• I didn't need to mow the lawn myself. My brother did it.我不需要自己刈草坪。我哥哥干了（从后一句看出“我”没有做）。

说了 needn't have + pp 之后，往往另加一句 could have + pp 作为一个替代办法。

• —I wanted a copy of the letter, so I typed it twice. —You needn't have typed it twice. You could have used a carbon. —我当时想给这封信留个底，所以打了两次。—你本来不需要打两次。你可以用复写纸嘛。

needn't have + pp 与 shouldn't have + pp 意义接近，但是后者多少带有一点“本来不应该”的责备口气，而前者则只是“本来不必”的惋惜口气。

• She shouldn't have stood in the queue. She should have got tickets from the machine.她本来不该站队。她应该到自动机器那里去买票（有责备口气）。
• She needn't have stood in the queue. She could have got tickets from the machines.她本来不必站队。她到自动机器那里去买票就行了（有惋惜口气）。

6) need not 有时候不是“不需要”，而是“不见得一定”。

• —She looks quite ill. I'm sure it's flu. —It needn't be —maybe she's just overtired. —她看样子病得很厉害。我看一定是流感。—那可不一定。也许只是劳累过度。

7) 后面如果接上动名词，要用主动形式表示被动意义。

• The machine needs oiling.机器需要上油了（不说 needs being oiled，但可以说 needs to be oiled）。
• Your hair needs cutting (needs to be cut).你的头发需要理一下了。

甚至后面说出施动者 (by whom) 时，need 后面（by 前面）的动名词仍然要用主动形式。

• This word needs replacing by (*being replaced by) a better one.这个单词应该用一个更好的来代替。