By whom is English taught to you?
Or
By whom are you taught English?
Solution:
For sentences that begin with "who", it will change into "By whom" in Passive voice. Below are the structures for active/passive voice:
Active: Who + verb (s or es) + object
Passive: By whom + is/are/am + object + verb (the past participle form)
Therefore, the passive sentence would be:
By whom are you taught English?
