Probably Won't and Might Not

"Probably won't" and "might not" are close in meaning, but "probably won't" means it is very likely that he won't become a doctor. "Might not" only means there is a chance he won’t become a doctor, but it is also likely that he will.

To understand the difference, it helps to look at the meaning of each word.

Probably means "very likely" or "almost certain." It tells us that it would be very easy for something to happen, there is a high chance that it will happen, or that we can almost be sure it will happen.

For example, if I say "I will probably be home at 5:00," we can assume that I will be home at 5:00 unless something happens to stop me, or make me late. As long as nothing goes wrong, I will definitely be home at 5:00.

Might is used to say that something is possible, or that there is a chance something will happen, but it is not certain, and we don’t know if it is the most likely possibility.

For example, if I say "I might be home at 5:00" it means that I will try to be home at 5:00, or I hope to be home at 5:00, and there is a chance I will be, but nothing is certain. There may be many reasons I won't be home at 5:00.

The sentence "He probably won’t become a doctor," means that it is very likely or almost certain that he won’t become a doctor. We can almost be sure he won’t become a doctor.

The sentence "He might not become a doctor" means he is doing everything he needs to do to become a doctor, but there is a chance he will not. Maybe he will change his mind, or maybe he will not finish school.

Probably is a much stronger word than might. Probably tells us something is much more likely to happen than might.

I hope this helps.