+0

(1) It would have been a good idea for him to have gone to that school.

Does sentence (1) alone provide sufficient information for the reader/listener to assume that "he" didn't in fact go to that school? Or do I need to follow it up with another negative/positive sentence to make the intended meaning clear, as in:

(2) It would have been a good idea for him to have gone to that school. But he didn't go there. Or

(3) It would have been a good idea for him to have gone to that school. But he went to another school.

In other words, could I use (1) if I don't know whether he really went to that school?

+1
Rizan MalikIn other words, could I use (1) if I don't know whether he really went to that school?

That seems just possible to me.

Jane: I remember when Harold was looking at Princeton.

Marie: It would have been a good idea for him to go to that school.

Jane: As it happens, he did go there in the end.

I got rid of the fussy perfect infinitive. "Would have been" gets the job done.

Rizan MalikDoes sentence (1) alone provide sufficient information for the reader/listener to assume that "he" didn't in fact go to that school?

Normally, yes. It defaults to that.