let me know when you see a gift that you like
If I were to translate that into the subjunctive what sounds more better "avísame cuando hubieras visto un regalo que te gusta" or "avísame cuando veas un regalo que te gusta"?
1 Answer
You don't need to use the imperfect subjunctive because you're talking about the future.
Avísame cuando hayas visto/veas un regalo que te guste.
(que te guste) because you still don't know if this gift exist... it can't please you if it doesn't exist.