Quote Originally Posted by BappaBa
Quote Originally Posted by Platinum
Dumb question. What is the difference between:
Они плавают. Они плывут.
Они плавают - They used to swim.
Они плывут - They swim.
Нет, used to как раз значит, что они больше не плавают.

I'd say
Они плавают. - They swim.
Они плывут. - They are swimming.

But
Они плавают can also be translated as They are swimming.

Could you think of a paticular situation?