Come by : Visit
I’ll COME BY after work and see if you need any help.
Come about : Happen, occur
The meeting CAME ABOUT because both sides were sick of fighting.
Come apart : Break into pieces
It CAME APART when I tried to lift it off the floor and I had to glue it back together.
Come round : Become conscious, wake up from anaesthetic
She CAME ROUND and learned that the operation had been a complete success.
Come up with : Think of a solution, excuse, etc.
Nobody could COME UP WITH a satisfactory explanation for the accident.