Remember for a past action when we know WHEN it happened, we use Past Simple. For example: I saw a panda yesterday
If we don’t say when it happened, we use Present Perfect.
For example: I have seen a panda (at some point in my life but I don’t say when)
In question we can say, “Have you seen a panda?’ (?Has visto una panda?)
‘Have you ever seen a panda? (?Alguna vez has visto una panda?)
Remember that in Present Perfect, we use the verb in the past participle. So if the verb is regular, it’s the same as the past simple but if the verb is irregular, the past participle is the THIRD form of the verb on the irregular verb list!
Now do the interactive exercise in Materials!