Hi Dolco, I am not sure I fully understand your question, but I will try to give you some examples that I hope will make things clearer for you. In your example sentences, the use of "could" (meaning "able to") implies past tense; perhaps the two people were together in the same room that morning, and person 1 asks whether person 2 could (=was able to) feel the cool breeze from outside in that room. Person 2 replies that they could (=were able to). In contrast, if person 1 has just turned on the AC and wants to ask whether person 2 can feel it, they would say "Can you feel the air from the AC?" and person 2 would say "Yes, I can really feel it." "Could" can also be used to politely request someone to do something. In such cases, "can" or "can't" can be used in the response. Q: "Could you please turn on the AC?" A: "Yes, of course I can." or "Sorry, I can't--it's broken." I hope that helps, and please let me know if I didn't answer your question.

@Gary // Thank you so much!!!

Sarah gave a good answer. Your example doesn't make sense though. AC doesn't give a 'breeze from outside', and as Sarah said, you would not say past tense 'could' when they have just turned it on.