Who gave you ice-cream?
Who gave you ice-cream? Correct Answer By whom were you given ice-cream?
By whom were you given ice-cream?In such case who will change into by whom.
Rule :
By whom + subject + (was /were) + V3 + other agents.
Who gave you ice-cream? Correct Answer By whom were you given ice-cream?
By whom were you given ice-cream?