查词 - when

1 at what time 什么时候

When are we leaving?

我们什么时候走？

When did you first meet Dr Darnall?

你是什么时候认识达纳尔博士的？

When will the work be finished?

这工作什么时候完成？

I don’t know when I’ll see her again.

我不知道何时才能再见到她。

when to do sth

I’ll tell you when to stop.

我会告诉你什么时候停下。

2 at or during the time that something happens 当〔某事发生〕时

Leonard was nine when his father died.

父亲去世时伦纳德九岁。

When the family came here from Russia, they were penniless.

那家人从俄罗斯迁来这里的时候身无分文。

When he was in the airforce he flew Tornado jets.

他在空军服役时驾驶龙卷风战斗机。

3 after or as soon as something happens 在〔某事发生〕后; 一…就…

When the meal was finished, Rachel washed up and made coffee.

吃完饭，雷切尔洗了餐具并泡了咖啡。

I’ll phone you again when I get home.

我到家后会再给你打电话。

4 used to mention a type of event or situation when talking about what happens on occasions of that type 当〔某种条件出现〕时会〔产生某种状况〕

When lead is added to petrol, it improves the car’s performance.

铅加在汽油中可以提高汽车的性能。

When mixed with water the powder forms a smooth paste.

和水混合以后，这种粉末会形成均匀的糊状。

He always wears glasses except when playing football.

除了踢足球，他总是戴着眼镜。

5 used to show which particular time or occasion you are talking about …的时候〔用于表示某一具体时刻或场合〕

The best moment was when he scored the winning goal.

最精彩的一刻是他射入致胜一球的时候。

There are times when I hate him.

我也有恨他的时候。

the day/time/afternoon etc when

She remembered the day when Paula had first arrived.

她想起了葆拉刚来的那一天。

6

by/since when

before or since which time 在…之前/自从…

The baby is due in May, by when the new house should be finished.

宝宝的预产期在 5 月，那时新房子应该造好了。

That was written in 1946, since when the education system has undergone great changes.

那是 1946 年写的，从那时起教育体制经历了巨大的变革。

7

since when...?

used to show that you are very surprised or angry [口] 从何时起〔表示惊讶或生气〕 spoken

Since when have you been interested in my feelings?

你从什么时候起开始关心起我的感受来了？

8 even though something is true 虽然; 尽管

Why does she steal things when she could easily afford to buy them?

她完全买得起，为什么还要偷东西呢？

9 used to introduce a fact or statement that makes something seem surprising 既然; 在…情况下; 如果

When you consider that the airline handled 80 million passengers last year, the accident figures are really very small.

如果你考虑到这家航空公司去年接待了 8,000 万名乘客，这个事故率其实是非常低的。