UPSC CDS English Spotting the Errors Part 2 Questions

The auxiliary verb ‘have’ is the root verb and is generally used alongside the pronouns (I, we, you and they) and plural nouns. ’Have’ is taken in Present Tense while ‘has’ is used alongside the pronouns (he/she/it and who) and singular nouns. The usage of the article ‘a’ shows that ‘tornado’ is singular and therefore ‘have’ must be replaced with ‘has’. Thus, option (a) is correct