There is a clear difference between afraid of and afraid for.
When you are afraid of, for example, snakes, you have a fear that snakes might harm you.
My little sister is afraid of spiders.
When you are afraid for someone, you fear that something bad might happen to them.
I’m afraid for you. Never go out alone late in the evening!
She had always been a typical mother hen, overprotective and constantly afraid for her children.
AFRAID FOLLOWED BY A VERB
Afraid can also be used with a verb.
There is a difference in meaning between these two:
Afraid of doing something (more general)
Afraid to do something (because of the potential result)
He was afraid of losing his girlfriend, but he was afraid to tell her about his fears.
I’m afraid of climbing high ladders.
The parcel had arrived but she was afraid to open it.
You can use the phrase I’m afraid to signal that something is impossible or untrue. If you ask to see your manager, the secretary might answer, ’I’m afraid she’s not in at the moment’. This means that the secretary knows that the manager is not there but wants to present the fact in a polite way. In some other languages the corresponding phrase indicates uncertainty, and the secretary will most likely go and check if the manager is in the office.
You can also use the phrase I’m afraid to soften disagreement or bad news:
I’m afraid you have misunderstood my intentions.
You have to leave now, I’m afraid.
I’m moving into my new flat on Saturday. Do you think you could give me a hand?
I’m afraid not. I’ll be away on a fishing trip over the weekend.