In written English, only is usually placed immediately before the word it qualifies. In spoken English, however, you can use stress to indicate what only qualifies, so its position is not so important.
1 adv 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.
ADV with group, ADV before v
Only the President could authorize the use of the atomic bomb..., Only here were the police visible in any strength at all..., 44-year-old woman seeks caring, honest male of similar age for friendship and fun. Genuine replies only..., A business can only be built and expanded on a sound financial base...
2 adv 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..., The Bank of England insists that it will cut interest rates only when it is ready...
3 adj If you talk about theonly 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..., My cat Gustaf was the only thing I had - the only company.
4 adj An only child is a child who has no brothers or sisters.
5 adv 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 may get or has already got.
ADV group, ADV before v
At the moment it is only a theory..., `I'm only a sergeant,' said Clements..., Don't get defensive, Charlie. I was only joking.
6 adv You use only to emphasize how small an amount is or how short a length of time is.
ADV n/adv (emphasis)
Child car seats only cost about £10 a week to hire., ...spacecraft guidance systems weighing only a few grams..., I've only recently met him.
7 adv You use only to emphasize that you are talking about a small part of an amount or group, not the whole of it.
ADV n (emphasis)
These are only a few of the possibilities..., Only a minority of the people supported the Revolution.
8 adv 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.
modal ADV inf (emphasis)
For a moment I could say nothing. I could only stand and look..., The police can only guess at the scale of the problem.
9 adv You can use only in the expressions I only wish or I only hope in order to emphasize what you are hoping or wishing.
ADV before v (emphasis)
I only wish he were here now that things are getting better for me...
10 conj Only can be used to add a comment which slightly changes or limits what you have just said.
It's just as dramatic as a film, only it's real..., Drop in and see me when you're ready. Only don't take too long about it.
11 conj 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..., I'd be quite happy to go. Only I don't know what my kids would say about living there.
12 adv You can use only before an infinitive to introduce an event which happens immediately after one you have just mentioned, and which is rather surprising or unfortunate.
Ryle tried the Embassy, only to be told that Hugh was in a meeting..., He raced through the living room, only to find the front door closed.
13 adv You can use only to emphasize how appropriate a certain course of action or type of behaviour is.
usu ADV adj, also ADV to-inf (emphasis)
It's only fair to let her know that you intend to apply..., She appeared to have changed considerably, which was only to be expected.
14 adv 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.
ADV before v
The embargo would only hurt innocent civilians..., She says that legalising prostitution will only cause problems.
15 If you say you only have to or have only 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.
have only to/only have to phrase V inflects, PHR inf (emphasis)
Any time you want a babysitter, dear, you only have to ask..., We have only to read the labels to know what ingredients are in foods.
16 You can say that something has only just happened when you want to emphasize that it happened a very short time ago.
only just phrase PHR before v, PHR adv (emphasis)
I've only just arrived..., The signs of an economic revival are only just beginning...
17 You use only just to emphasize that something is true, but by such a small degree that it is almost not true at all.
only just phrase usu PHR before v, PHR with cl/group (emphasis)
For centuries farmers there have only just managed to survive..., I am old enough to remember the Blitz, but only just...
18 You can use only too to emphasize that something is true or exists to a much greater extent than you would expect or like.
only too phrase PHR adv/adj (emphasis)
I know only too well that plans can easily go wrong..., When the new baby comes along it is only too easy to shut out the others.
19 You can say that you are only too happy to do something to emphasize how willing you are to do it.
only too phrase PHR adj (emphasis)
I'll be only too pleased to help them out with any queries.
the one and only