11.get a head start on something -> begin doing something early
早早地开始干某事
Let's get a head start on the report tomorrow.
每天我们早点开始报道吧。
She got a head start on her homework immediately after school.
一放学，她早早地就开始写起作业。

12.get your head above water-> keep going in life despite many difficulties
困难重重，却仍然坚持
If I can find a job I'll be able to get my head above water.
如果我能找到工作，就能维持生活了。
Study these pages and you'll get your head above water.
学习这几页的内容，你就能明白了。

13.get someone or something out of one's head -> remove someone or something from your thoughts (often used in the negative)
将某人或某事从你的脑子里脱离出去
I'm really upset that I can't get her out of my head.
我忘不了她，这使我很难受。
She spent three years getting those experiences out of her head.
她花了三年的时间将这些经历从脑海中忘记。

14.give someone a head's start -> let someone else begin before you in  a competition of some kind
在比赛中让某人先开始
I'll give you twenty minutes head's start.
我先让你来20分钟。
Can you give me a head's start?
你能让我先开始吗？

15.go over someone's head -> not be able to understand something
无法理解某事
I'm afraid the joke went over her head.
恐怕她听不懂这个笑话。
I'm afraid the situation goes over my head.
我恐怕还无法理解情况。

16.go to someone's head -> make someone feel better than others
使某人觉得自己比他人优秀
His good grades went to his head.
他的好成绩使他觉得自己比别人更优秀。
Don't let your success go to your head. Stay humble.
不要被胜利冲昏了头。谦虚一点。

17.have a good head on your shoulders -> be intelligent
聪明的
She's got a good head on her shoulders.
她非常聪明。
You can trust him because he's got a good head on his shoulders.
你可以相信他，因为他十分聪明。

18.head someone or something off -> arrive before someone or something else
比别人先到达
Let's head them off at the pass.
先发制人。
We need to head the problem off.
我们需要比别人先解决这个问题。

19.hit the nail on the head -> be exactly right about something
一针见血
I think you hit the nail on the head.
我觉得你真是一针见血。
His answer hit the nail on the head.
他的答案说到点子上了。

20.in over one's head -> do something that is too difficult for a person
某事对某人而言太难了
I'm afraid Peter is in over his head with Mary.
恐怕玛丽无法对付皮特。
Do you ever feel that your in over your head?
你有没有感觉到自己做的事难于登天？

21.lose your head -> become nervous or angry
变得紧张或愤怒
Don't lose your head over the situation.
面对这种情形不要紧张。
She lost her head when he told her he wanted a divorce.
当他告诉她想离婚时，她愤怒了。