Read about using different structures with wish below. Then, when you are ready, try these wish / if only practice exercises.
Using wish with past verbs
You can use "wish" to talk about the future (with a similar meaning to "want") like this:
I wish to make a complaint.
However, this isn't very common in spoken English - it sounds very formal. It's more common to use "wish" to talk about imaginary situations.
I live in a small flat. I wish I lived in a castle!
I wish I had bought a bigger house.
The tense you use after wish depends on whether you are talking about the past or present.
I wish I lived in a castle
wish + past simple = imaginary present time
I wish I'd bought a big house
wish + past perfect = imaginary past time
We can use if only in exactly the same way as I wish. For example:
If only I lived in a castle!
Supposing / suppose and imagine can also be used with the past simple and past perfect.
Suppose I lived in a castle! That would be wonderful!
Imagine I had bought a bigger house. I wouldn't have any money now!
We also use the past simple after it's time and it's high time:
It's (high) time we went.
(meaning "we should go now")
Wish / if only: advanced points
It is also possible to use wish / if only + would when we talk about present habits or future possibilities. It means something is possible, but you don't think it will happen. It is often used to show you are annoyed with something / someone.
I wish Maria spoke English.
I wish Maria would speak English.
In the first example, Maria doesn't (can't) speak English. In the second example with would, she can speak English, but she chooses not to. Here, would could be seen as the past of will with the meaning "Please will you speak English!"