happen、occur、chance与take place这些词语都可表示“发生”之意。
happen : 普通用词，泛指一切客观事物或情况的发生，强调动作的偶然性。
- Anything could happen in the next half hour.
接下来的半小时内什么事都可能会发生。 - A funny thing happened in the office today.
今天，办公室里发生了一件有趣的事。 - I don't want to think about what might have happened if he'd been driving any faster.
我不愿意去想假如他再开快些会怎么样。
occur : 较正式用词，可指意外地发生，也可指意料中的发生。
- An accident involving over ten vehicles has occurred in the east-bound lane.
在东向车道上发生了一起涉及十多辆汽车的交通事故。 - If any of these symptoms occur while you are taking the medication, consult your doctor immediately.
服药期间如果产生了这些症状中的任何一种，要立即就医。
chance : 侧重事前无安排或无准备而发生的事，特指巧合。
- They chanced to be in the restaurant when I arrived.
我到的时候他们正好在餐馆里。 - I chanced on/upon (= found unexpectedly) some old love letters in a drawer.
我偶然在抽屉里发现了一些旧情书。
take place : 多指通过人为安排的发生。
- The concert takes place next Thursday.
音乐会下星期四举行。
