‎Hi! “It's (high) time+pronoun+past verb form”
I was talking with a native speaker the other day and he told me we should use infinitive after this expression, but according to the grammar book, we can never use infinitive in this case.
Only if we were to say something like: it is time for us to...
And I really want to know your opinion. Does it even sound natural? For instance: It's (high) time we bought presents.
And also, is "high" often used there, or is it rather an obsolete language structure?
It's just that I want to speak correctly in terms of grammar, but I don't want to sound like a dialogue from a grammar textbook…

Question

Answer

'It's time' is often followed by an infinitive:
It's time to buy a new shirt.

It can also be followed by past tense:
It's time he was in bed.

Likewise, 'It's high time' is followed by past tense:
It's high time you got out of bed.

However, I don't think it would sound natural to use 'It's high time' followed by infinitive. For example:
It's high time to get out of bed.* (This would sound rather odd.)