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I am afraid I can't come tomorrow / I am afraid I won't be abel to come tomorrow
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Abel is the name of a biblical pesonality. Change it to able, and both versions are fine.
Comments  
Students: Are you brave enough to let our tutors analyse your pronunciation?
I am afraid I can't come tomorrow.
I am afraid I won't be able to come tomorrow.

I see no difference in meaning.

Prajwal

Both are correct.

But (I'm afraid I won’t be able to come tomorrow) is more meaningful than (I can’t...)