in/within (a week)

当句子动词为将来时时, in a week 是指从现在算起历时大约一周的时间 (at the end of a period of a week starting from now, in a week's time)。因此, in a week 是指一周后或过一周, 即大约历时一周的时间, in five days 是指五天后或过五天, 即大约历时 5 天的时间。

1. We'll meet you in a week. 过一周我们去见你。

2. He'll arrive in three days. 他三天后到达。

3. I told him the money would be paid back in six months. 我告诉他钱将在六个月后还清（或：我告诉他过六个月把钱还清）。

4. In another five minutes it'll be pitch dark. 再过 5 分钟天就会漆黑了。

5. The train will arrive in three hours. (IME) 火车再过三小时到达。

6. Richard will be back in a few minutes. (IME) 理查德几分钟后就回来。

但是,当动词为过去时时(She finished the job in a week), in a week 则是指“一周之内”,即从过去某一个时间点向后算起的一周之内(in the space of a week from when she started it)或者经过了一周的时间(可译为:“一周内”“过了一周”)。

1. It developed from a small club into a mass organization in three years. 它在三年之内从一个小俱乐部发展成为一个庞大的组织。

2. In two weeks Jules had done so. Five Weeks in a Balloon became a best seller. (RL, Book 2, L.16) 朱尔斯·凡尔纳用两周时间写完了这本书。《在气球上的五周》成了畅销书。

3. In a few minutes he returned with my bag and gave it back to me. (New Concept English, Book 2, L.18) 过了几分钟，他拿着我的皮包返了回来，把皮包还给了我。

within a week 则总是指“一周之内”。另外, within 比 in 较为正式:

1. I shall be back within a week. 我将在一周之内返回(可能三天后,也可能五天后返回)。

2. Sixteen houses were vandalized within a few weeks. (EED) 16 所房子几周之内就被破坏了。

3. Though they extol the virtues of the peaceful life, only one of them has ever gone to live in the country and he was back in town within six months. (New Concept English, Book 3, L. 41) 虽然他们喜欢侈谈宁静生活的乐趣，但是，他们中间仅有一个人曾在乡村生活过，而且不满半年就返回了城市。

4. Marvin and Terry were quarrelling within a month of their marriage and were separated within three months. (CGEL) 马文和特丽在他们结婚的一个月之内就吵架，而在三个月之内便离婚了。

5. The form is to be filled in and returned within three weeks. (PEU) 请将表填好并于三周内寄回。

in a day