If you talk about the only person or thing involved in a particular situation, you mean there are no others involved in it.
She was the only woman in Shell's legal department.
她曾是壳牌公司法律部唯一的女性。
An only child is a child who has no brothers or sisters.
The actor, an only child, grew up in the Bronx.
那位演员是个独生子,在布朗克斯区长大。
You use only to indicate the one thing that is true, appropriate, or necessary in a particular situation, in contrast to all the other things that are not true, appropriate, or necessary.
Only the president could authorize the use of the atomic bomb.
只有总统能授权使用原子弹。
A business can only be built and expanded on a sound financial base.
一家企业只有在稳定的财政基础上才能创立并扩大规模。
You use only to introduce the thing which must happen before the thing mentioned in the main part of the sentence can happen.
The lawyer is paid only if he wins.
律师只有打赢官司才能收费。
The Bank of England insists that it will cut interest rates only when it is ready.
英格兰银行坚持只有在它做好准备时才会降低利率。
You use only to indicate that something is no more important, interesting, or difficult, for example, than you say it is, especially when you want to correct a wrong idea that someone has or may get.
just
At the moment it is only a theory.
眼下,这还只是个理论而已。
'I'm only a sergeant,' said Clements.
“我不过是个中士,”克莱门茨说。
You use only to emphasize how small an amount is or how short a length of time is.
Child car seats only cost about $10 a week to rent.
儿童汽车座椅一周的租金仅约10美元。
spacecraft guidance systems weighing only a few grams.
只有几克重的宇宙飞船导航系统。
You use only to emphasize that you are talking about a small part of an amount or group, not the whole of it.
These are only a few of the possibilities.
这些只是其中的几种可能性。
Only is used after 'can' or 'could' to emphasize that it is impossible to do anything except the rather inadequate or limited action that is mentioned.
For a moment I could say nothing. I could only stand and look.
一时间我什么也说不出来,只能站在那儿看着。
You can use only in the expressions I only wish or I only hope in order to emphasize what you are hoping or wishing.
just
I only wish he were here now that things are getting better for me.
现在我的情况好转了,我真希望他能在这儿。
You can use only before an infinitive to introduce an event which happens immediately after one you have just mentioned, and which is surprising or unfortunate.
Ron tried the embassy, only to be told that Hugh was in a meeting.
罗恩到使馆试了试,却被告知休正在开会。
You can use only to emphasize how appropriate a certain course of action or type of behaviour is.
It's only fair to let her know that you intend to apply.
要让她知道你有意申请,这才公平。
You can use only in front of a verb to indicate that the result of something is unfortunate or undesirable and is likely to make the situation worse rather than better.
The embargo would only hurt innocent civilians.
禁运只会伤及无辜的平民。
Only can be used to add a comment which slightly changes or limits what you have just said.
but , except
It's just as dramatic as a movie, only it's real.
这就像电影一样充满戏剧性,不过这是真实发生的。
It's a bit like my house, only nicer.
这有点儿像我的房子,不过更漂亮些。
Only can be used after a clause with 'would' to indicate why something is not done.
I'd invite you to come with me, only it's such a long way.
要不是路途太远,我就请你和我一起去了。
only have to
If you say you only have to do one thing in order to achieve or prove a second thing, you are emphasizing how easily the second thing can be achieved or proved.
Any time you want a babysitter, dear, you only have to ask.
亲爱的,你什么时候需要有人帮忙照看孩子,只要开口说一声就行。
only just
You can say that something has only just happened when you want to emphasize that it happened a very short time ago.
I've only just arrived.
我刚到。
You use only just to emphasize that something is true, but by such a small degree that it is almost not true at all.
For centuries farmers there have only just managed to survive.
几个世纪以来,那儿的农民勉强能维持生计。
I am old enough to remember the War, but only just.
那场战争发生的时候我已开始记事,但也只是仅仅有些模糊的印象。
only too
You can use only too to emphasize that something is true or exists to a much greater extent than you would expect or like.
I know only too well that plans can easily go wrong.
计划很容易出问题,我再清楚不过了。
You can say that you are only too happy to do something to emphasize how willing you are to do it.
I'll be only too pleased to help them out with any questions.
我十分乐意为他们解决任何问题。