Here are some options and their uses:
For ability:
* முடியும் (mudiyum): This is the most common word for "can" or "is able to." It can be used to express the ability to do something in the past, present, or future.
* சாத்தியம் (saathiyam): This means "possibility" and can be used to express the ability to do something, especially when the likelihood is uncertain.
For possibility or permission:
* இருக்கலாம் (irukkalam): This literally means "it might be" and can be used to express possibility or permission in a tentative or uncertain way.
* ஆகலாம் (aagalam): This means "it could be" and is similar to "irukkalam" but implies slightly more certainty.
* சாத்தியம் (saathiyam): This can also be used to express possibility or permission.
For hypothetical situations:
* நான் ... என்று (naan ... enru): This is a structure that means "if I... then...". It can be used to express hypothetical situations where "could" is used to indicate a possibility.
Examples:
* "He could speak Tamil" - *அவர் தமிழ் பேச முடியும் (avar tamil pesha mudiyum)* (He can speak Tamil.) OR *அவர் தமிழ் பேச ஆகலாம் (avar tamil pesha aagalam)* (He could speak Tamil.)
* "I could go to the store" - *நான் கடைக்கு போகலாம் (naan kadikku pogalam)* (I could go to the store.)
* "If I had more time, I could do it" - *எனக்கு நேரம் இருந்தா, நான் அதை செய்ய முடியும் (enakku neram iruntha, naan adai seiya mudiyum)* (If I had time, I could do it.)
It's important to consider the specific context and desired nuance when choosing the best word for "could" in Tamil.