Interested in Language
a," Could I ask you sth, if you are not too busy?"
b,"Yes, of course you can/ could."
Both "can" and "could" are fine, right? Please.
As a Brit and mentor, but not a teacher I would advise as follows:
In the 1st sentence, the word "could" implies "can I (if you give me permission)"
In the 2nd sentence, the word "can" is correct, as you are giving that permission.
"Could" would suggest that there is another reason why they may not be able to ask the question.
Hope this helps