We use 'many' to talk about a large number of things we can count. It is used with plural nouns. It helps to show there is more than a few.
Many books are on the table.
She has many friends at school.
'Many' can act like a pronoun when it replaces plural countable nouns. It means a lot of people or things but does not say exactly how many.
Many have said yes to the plan.
Many are ready to start work now.
'Many' is often used in questions and negative sentences to ask about or talk about numbers of things we can count. It shows quantity but not exact number.
How many apples do you want?
She does not have many toys.
'Many' can be used figuratively to mean a big amount or many different kinds of things, not only exact numbers. It is common when talking about ideas, reasons, or examples.
She has many ideas about health.
Many reasons explain this problem.
Sometimes in informal or regional British English, 'many' is used with uncountable nouns incorrectly. This is nonstandard but often heard in speech. Normally, 'much' is correct for uncountable nouns.
Do you have many homework today? (nonstandard)
How many money did you spend? (incorrect but common)
In older or formal English, 'many' can act like an adverb meaning 'much' or 'a lot' to show how often or how much something happens. This usage is rare today.
I did not like it many years ago.
The place has changed many times.
