wish

In English, you can use “wish” and “if only” to talk about wishes and hypotheses.^[1]https://learnenglish.britishcouncil.org/grammar/intermediate-to-upper-intermediate/wish-and-if-only

The main difference is that “if only” is a stronger expression for wishes and hypotheses.  

Wishes in the Past

You can use “wish” or “if only” with the past perfect tense to talk about what you would like to change about the past.

For example:

• They wish they had studied more for the test.
• If only I had closed my window before I left, then the robbers wouldn’t have been able to get into the house.
• She wishes that she had prepared more for the driving test.

Wishes in the Present

You can use “wish” or “if only” with the past simple and past continuous to talk about what you would like to change in the present.^[2]https://learnenglish.britishcouncil.org/english-grammar-reference/wishes-and-hypotheses

For example:

• I don’t like this food. I wish I chose something different.
• I don’t like this seat in the car. If only I were sitting in the front seat.
• I’m dying here. If only it was not so hot here!

Wishes in the Future

You can use “wish” or “if only” with the modal verbs “would” and “could” to talk about what you would like to do in the future.

For example:

• I don’t like my job. I wish I could quite, but if I quite then I won’t have any money!
• If only I would have studied more, then I would have easily passed the test.
• I wish I could stop smoking. It is a very bad habit.