what's the construction?

I have recently come across a strange construction in the book:

‘Many a visitor has struggled to find Petticoat Lane’.

Is ‘many a …’ commonly used? Why no to write ‘many visitors have struggle to …’?

No, it’s not a strange construction. The usage is correct. ‘Many a’ is an expression meaning just ‘many’. So ‘many a visitor’ means ‘many visitors’. But you need to use a singular verb after ‘many a’ as in your sentence.

Thank you!

It is often used in a quasi poetical/literary way rather than in ordinary spoken English - an example -

youtube.com/watch?v=dqUImQmqQ7s

I very nearly didn’t click the link, but I’m glad I did. Nat King Cole has to get lost in! (IMHO, of course).

Thank you, Alan!

Beeesneees, what does ‘I very nearly didn’t click the link’ mean? ‘Very nearly’ in the negative sentence confuse me a bit.

‘Very nearly’ means ‘almost’ - I was late getting to the station and I very nearly missed catching the train because I arrived one minute before it left.

You could say - I very nearly didn’t catch the train.