The Phrase ‘many a’ takes a Singular or a Plural Verb?
Whether the idiom many a requires a singular or a plural verb often causes confusion. Sir Ernest Gowers in his The Complete Plain Words explains it very lucidly when he says that “owing to the pull of the singular a, the expression many a always takes a singular verb”. He also adds that the expression “There’s many a slip betwixt the cup and the lip” is idiomatic English.
In Modern American Usage, Bryan Garner, says that many a requires a singular verb “essentially because the idiom is distributive rather than aggregate in sense.” He also draws attention to the fact that W. H. Fowler pointed out in 1926 (Modern English Usage) that “writers sometimes incorrectly make the verb plural when using an inverted construction” such as:”They have (read has] many a night in Calcutta when they just can’t sleep because of the heat and humidity.”
In The New Fowler’s Modern English Usage, R. W. Burchfield opines that many a prophecy though notionally plural [=many prophecies] always requires a singular verb. Even the phrase many another would require a singular verb.