প্রশ্ন: Hardly ___ entered the office when he realized he forgot his wallet.
(ক) he had
(খ) he was
(গ) had he
(ঘ) did he
ব্যাখ্যা:
Rule: Hardly + had + subject + V3, when clause। এটি fixed inversion structure। যেমন: Hardly had I reached when it started raining.