Hypothetical Past

The hypothetical past is used in English to refer to an unreal situation. So, although the verb tense is in the past, we are actually talking about something that didn't happen. This is often the case in conditional sentences.

1. wish/if only/I’d rather/I’d sooner  + past perfect: wishes, regrets, criticisms

I wish I’d learnt (learned) to ski properly.

If only I had owned a dog when I was younger.

I’d sooner taken up an apprenticeship than gone to university

2. should + perfect infinitive: regrets and criticisms

We should have worn rain boots. We’re all wet.

You shouldn’t have lied to me. Now I can’t trust you.

3. (Third conditional) if + past perfect, would/might/could + perfect infinitive: to speculate  about how things might have been different in the past.

If only I had ridden a motorcycle more routinely, I might not have had my accident.

Had I studied, I could have passed the course.