Q. Fill the correct form of verb in the given sentence. Many a man ________ died for his country.

Explanation:

Rule: The expression ‘many a/an + singular noun’ takes a singular verb. Hence, the correct form is ‘has’ with the past participle ‘died’ (present perfect): Many a man has died for his country.
Why others are wrong:
– was → ‘was died’ is ungrammatical; ‘die’ is intransitive and cannot take a passive form. (‘was dead’ would change the meaning.)
– is → ‘is died’ is incorrect; ‘is dead’ would be different in meaning and tense.
– have → plural verb; disagrees with the singular subject after ‘many a’.