I know that we say
I would rather read a book than go out now.
How about in a case in which you went out last night but you feel regret about it? Is using "would rather " grammatically correct or common in these situations?
"I would rather hadn't gone to party. It was terrible."
or can we can only use the word "wish" for these situations?
"I wish I hadn't gone to the party. It was terrible."
Best Answer
As Jim points out, the ordinary way of saying this employs not+infinitive, just as your first example would if it were negated:
When you employ a finite verb in the second clause you have to supply a subject for it, even if it is the same subject as that of the main clause:
But versions with repeated subjects may sound odd to some people, particularly in conversation.
In any case, the rather constructions really express preference rather than regret. I suggest you avoid rather, and stick with wish in these situations.