He smokes too much. He can't get rid of his cough.

50/50

If he didn't smoke so much, he could get rid of his cough.

If he smokes so much, he can't get rid of his cough.

If he didn't smoke so much, he can get rid of his cough.

If he smoked so much, he could get rid of his cough.

Giải thích

Câu điều kiện loại 2 (không có thật ở hiện tại):

If + S + V (QKĐ/ were) + O, S + would/could/should/might + V-inf + O.

Dịch nghĩa: Anh ấy hút thuốc quá nhiều. Anh ấy không thể hết ho. = Nếu anh ấy không hút thuốc quá nhiều, anh ấy có thể hết ho.