Re: Possibility or Suggestion
As an American, I wouldn't use "might" for past permission (as I saw in a recent post) or suggestion.
- You may leave the table when you've eaten your vegetables (current permission)
- Yesterday, you could have/were allowed to leave the table when... (past permission) - would not use "might have" there.
- You may have found a solution! (present possibility)
- Yesterday, you might have found the solution we have been looking for. It's still being tested.
- You may/might want to ask someone who knows about this stuff (present suggestion)
- May/Might I open the window? Request. American are less likely to use "might" here, I believe.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.