副词

连词

学校

结婚纪念日

旅游

1. (用于疑问句)什么时候，何时
You use when to ask questions about the time at which things happen.

2. (表示两事同时发生)在…时，当…时
If something happens when something else is happening, the two things are happening at the same time.

3. (引导从句，表示某事发生于另一活动、事件或情形期间)在…的过程中
You use when to introduce a clause in which you mention something which happens at some point during an activity, event, or situation.

4. (引导从句，说明主句动作已经发生或将要发生时的情况)其时
You use when to introduce a clause where you mention the circumstances under which the event in the main clause happened or will happen.

5. (尤用于动词和形容词后引导从句，表示某事发生的时间)什么时候,何时
You use when after certain words, especially verbs and adjectives, to introduce a clause where you mention the time at which something happens.

6. (用于引导从句，限定或指示某事发生的时间)…的时候
You use when to introduce a clause which specifies or refers to the time at which something happens.

7. (用于引出某个观点、评论或问题的原因)既然，考虑到
You use when to introduce the reason for an opinion, comment, or question.

8. (用于引出使句子的其他部分显得让人吃惊或不大可能的事实或评论)虽然，然而,可是
You use when in order to introduce a fact or comment which makes the other part of the sentence rather surprising or unlikely.