I found a grammar rule about when to choose "who" and "whom".
Rule. Use this he/him method to decide whether who or whom is correct:
he = who
him = whom
So I have a question about correctness of the following question:
Who should I give this job to?
According to this rule we should have used whom instead of who, because I should give this job to him, not I should give this job to he. But there's a man who keeps telling me that
Whom should I give this job to?
is wrong. Please clarify?