这些名词均有“事故、事件”之意。
1. accident 强调偶然或意外发生的不幸事情。如：
He has had a bad accident. 他出了严重事故。
Car accidents are far too common. 汽车事故是太常见了。
Philip will give him details of the accident. 菲利普将给他谈这次事故的详细情况。
The accident took place only a block from, his house. 事故发生的地点离他家只有一个路段。
After the accident, the injured were taken to hospital. 事故发生之后受伤的人被送往医院急救。
2. incident 既可指小事件或附带事件，又可指政治上具有影响的事件或事变。如：
Please accept my apologies for this unfortunate incident. 发生了这件不幸的事请接受我的道歉。
The incidents affected him for days. 这些事件使他好几天心情不能平静。
The witness gave a truthful account of the incident. 证人真实地描绘了这个事件。
3. event 可指任何大小事件，但尤指历史上的重大事件。如：
The event was fatal to my hopes. 这次事件粉碎了我的希望。
At the beginning of June an event occurred. 六月初发生了一件事。
The event was fatal to my hopes. 这次事件粉碎了我的希望。
4. occurrence和happening这两个词多指日常生活中发生的一般事件，有时也指偶然发生的事。如：
So being killed by sharks was a common occurrence. 因此被鲨鱼咬死是常有的事。
What schoolboy of fourteen is ignorant of this remarkable circumstance? 14岁的学生在这件值得注意的事件中会忽略掉什么呢?
There were some unusual happenings at school last week. 上星期在学校里发生了一些不寻常的事。