Who called you a liar? বাক্যের Passive Voice হচ্ছে-
By whom are you called a liar?
By whom were you called a liar?
Correct
By whom you called a liar?
By whom was you called a liar?
Explanation:
Correct Answer is: By whom were you called a liar?
Who called you a liar? বাক্যের passive voice হচ্ছে – By whom were you called a liar?
মূল sentence `past indefinite` হাওয়ায় you এর auxiliary verb হিসেবে were বসবে।