In the present

We can use wish/if only + a past form to talk about a present situation we would like to be different. 

I wish you didn't live so far away.
If only we knew what to do.

In the past

We can use wish/if only + a past perfect form to talk about something we would like to change about the past. 

They wish they hadn't eaten so much chocolate. They're feeling very sick now.
If only I'd studied harder when I was at school. 

Expressing annoyance

We can use wish + would(n't) to show that we are annoyed with what someone or something does or doesn't do. We often feel that they are unlikely or unwilling to change.

I wish you wouldn't borrow my clothes without asking.