首先OK可以写成：
O.K.
o.k.
okay
从词性分有四种之多：
1.形容词
安然无恙；平安；快活；可以；可行；尚可；不错，好了
Are you OK?
你没事吧？
She says she's OK now, and will be back at work tomorrow.
她说她现在身体还可以，明天就回来上班。（指感觉身体还好、没有生病、没有受伤等）
You look rough ─ are you OK?
你看上去不太舒服——没事吧？
Is cold meat and salad OK for lunch?
午饭吃冷肉和色拉行吗？
Is it OK if I leave now?
我现在离开，可以吗？
Is it OK for me to come too?
我也去，行吗？
Is it OK if I post you the cheque next week?
我下周寄给你支票可以吗？
I kept telling myself everything was OK.
我不住告诉自己一切都没问题。
Does my hair look okay?
我的头发还看得过去吗？
It's OK, you're among friends now.
好了，现在你的周围都是朋友了。
I think I did OK in the exam.
我觉得我考得还不错。
Whatever you decide, it's okay by me.
无论你怎么决定对我来说都行。
Is everything OK/all right?
一切正常吗？
an okay movie
一部不错的电影
Relax! Everything will be OK.
别着急！一切都会好的。
可以是表语，也可以是定语。
2.副词
好，运行得好，愿意，或肯定愉快的答复
The car goes okay now.
那辆汽车现在跑得很好。
Are you willing to help her?
OK.
你愿意帮助她吗？愿意。
I think I did OK in the exam.
我觉得我考得还不错。
3.名词,肯定愉快干脆的答应或许可
I'm still waiting for the boss to give me the OK.
我还在等上司点头呢。
Click the OK button to start.
单击确认键启动。
She got an OK on it.
她此事已得到许可。
Have they given you their O.K?
他们已经同意你了吗？
We have Coach Smith’s OK to use the gym this Monday.
我们已经得到史密斯教练的同意，可以在本星期一使用体育馆。
4.动词 批准，许可
过去式，过去分词，都是OK'd
第三人称单数是 OK's, 现在分词是OK'ing
She filled in an expenses claim and her manager OK'd it.
她填写了一张费用申报单，她的经理批准了。
The editor O.K.’d the manuscript for publication.
编辑批准此稿件付印出版。
Since the manager was not in, his secretary OK’d the requisition.
由于经理不在，他的秘书批准了这项申请。
