It is vital to place the word only correctly in your sentence. That position is usually just before the word it refers to or qualifies.
To see what i mean, take this simple sentence.
The Bishop gave the baboon a bun.
Now pop the word only before each word in turn.
I know you can do it by yourself - but I want to have fun also.
Only the Bishop gave the baboon a bun.
The only Bishop gave the baboon a bun.
The Bishop only gave the baboon a bun.
It's even more fun reading the sentences aloud. The last one should have a deeply apologetic tone because clearly the baboon had suffered as a result of its treat. Now carry on by yourself.
Note to any teachers reading this: your pupils will love it.