Hi Silvia. In the example, "Tal vez yo haya estudiado mucho para el examen," the English translation says, "I might have studied a lot for the exam". Is that "I might have studied a lot" in the sense "maybe I would have studied a lot [if I had time?"] Or "Perhaps (it possible) I studied a lot for the exam"? Both?
Oh wait, after writing this I realized that the sentence perhaps means, "I should have studied a lot for the exam.” We Americans almost never use the word “might” in this sense. I’m not sure how much you Brits (all British residents) do. Is this the sense in which it is used here?