Past tense for hypothetical meanings: Wish/if only etc.

Past tenses for hypothetical meanings
We use past tenses after the following expressions to describe situations in the present, past or future which are imagined or unreal:

wish / if only, It's (high) time, would rather/sooner, would prefer, as if/though, suppose/supposing, what if

A wish / if only
1 We use wish / if only + past when we want a present situation to be different:
I wish / If only we had more money. (but we haven't)
I wish I was (formal: were) a bit taller. (but I'm not)
2 wish + would is used to express a wish for something to change in the present or future.
• We often use it to criticise or complain about someone or something:
I wish Peter would wear smarter clothes. I wish the weather would improve.
• I wish + would cannot be used to refer to oneself:
I wish I could (not would) stop smoking. (but I can't)
• We cannot use would for an impossible change:
If only the earth was (formal: were) square.

Note
Notice the difference between wish and hope. If we hope something will happen, we believe it is possible and likely:
I hope they will come. (= I want them to and I think it's likely.)
I wish they would come. (= I don't believe it's likely.)

3 We use wish / if only + past perfect to express regret about a past situation:
I wish we'd had something to eat earlier. (but we didn't)
If only I hadn't missed my appointment. (but I did)

4 Differences between wish and if only.
• if only is usually more emphatic than I wish.
• We can put a subject between if and only for emphasis:
If only you / If you only knew what I've been going through.

B It's time
We use this expression to say that something is not happening and it should be:
It's (high) time you gave up playing computer games. (You should give them up!)

C would rather/sooner, would prefer
I'd rather / I'd sooner you didn't ask me for any more money. (Please don't!)
I'd prefer it if you didn't ask me for any more money.

Notes
• If the speaker and the preference are the same, we use an infinitive, not the past tense:
I'd rather/sooner watch TV. (not Fe watch)
I'd prefer to watch TV (not-watch)
• We can also say I'd prefer you not to go.

D as if/ as though
• We use the past after as if/as though to indicate that the situation is unlikely:
He acts as if/though he was (formal: were) a teenager. (In fact, he's in his thirties.)
• We use a present tense to indicate that something is likely:
He looks as if/though he is a teenager. (And he probably is.)

E suppose/supposing, imagine, what if
We use these expressions to ask about an imaginary situation in the present or future, and its possible consequences:
(just) suppose/supposing/imagine you won the lottery, how would you spend the money?
What if you had hurt yourself-what would have happened then?