Speak to/with someone
Incorrect : I shall speak him about it.
Correct: I shall speak to/with him about it.
Note: "Speak' can be used as a transitive verb like this:
He spoke the truth.
But this verb cannot take “the person spoken to as an object. "I shall speak to him” means "I shall do all the speaking' but “I shall speak with him” means “I shall have a conversation with him”.