what ____to you?you looks terrible

what happened to you?

1. sth.+happen+地点/时间，意为某地/某时发生了某事。例如：
An accident happened in that street.
那条街发生了一起事故。
What's happening outside?
外面发生什么事了？
2. sth.+happen to+sb.意为某人出了某事(常指不好的事发生在某人身上)。例如：
A car accident happened to him yesterday.
昨天他发生了交通事故。
What happened to you?(=What was wrong / the matter with you?)
你怎么啦？
3. sb.+happen+to do sth.意为某人碰巧做某事。例如：
I happened to meet her in the street.
我碰巧在街上遇见她。
It happened that I was out when he called.
他来访时我碰巧不在。
4. happen为不及物动词，不能用于被动语态。例如，要表示这个故事发生在去年。不能说：The story was happened last year.但可以说：The story happened last year.
5. happen为短暂性动词，不能与表示一段时间的状语连用。例如，要表示这事发生一年了。不能说：This happened for one year.但可以说：This happened one year ago.
6. happen一般用来强调某事发生的偶然性。如要表示事先安排或有准备的事情或活动，则不能用happen，而要用take place。例如：
A sports meeting took place(=was held) in our school last week.上周我校举行了运动会。(不能说：A sports meeting happened in our school last week.)
7.hap