0 used mainly in negative sentences and questions and with "too", "so", and "as" to mean "a large number of": --
She had five children in as many (= in the same number of) years and decided it was enough.
A good/great many people who voted for her in the last election will not be doing so this time.
There are already twelve bottles of wine, so if I buy as many again (= another twelve bottles) we'll have enough.
As many as (= the surprisingly large number of) 6,000 people may have been infected with the disease.
If there were as many women as there are men in parliament, the situation would be very different.
If there are only five of us going to the concert, then I've booked one too many seats.
I've met him so many times and I still can't remember his name!
I don't have many clothes.
The school has pupils from many different ethnic and cultural backgrounds.
There are too many silly quiz shows on television these days.
High prices are deterring many young people from buying houses.