Someone else has asked a similar question but in regards to the interchangeability of the tenses, if you were to say "You could have called me the whole evening", can you still say "Podrías/Podías haberme llamado toda la tarde" or do you have to use "Pudiste haberme llamado toda la tarde" because it is in a set time frame now?
Generally, using one tense or another comes with a nuance, i.e. considering the action as a completed action in the past (preterite) or expressing this action with no relevance towards when it ended (imperfect), for example, but in this case, with poder, that nuance is not perceived and I would say all three tenses reflect the same meaning.
Sign in to submit your answer
Don't have an account yet? Join today
Test your Spanish to the CEFR standard