Question

Why does malcolm lie about himself to macduff

Answer 1

To test him

Step-by-step explanation:

Malcolm was testing Macduff's trustworthiness and loyalty to him.

Answer 2

Malcolm lied about himself to Macduff to test him; to make sure he was not bribed by Macbeth. He had to do this in order to see if Macbeth/Macduff would try to overthrow the throne.