countable nouns

For positive sentence we can use a/an for singular nouns or some for plurals.

There's a man at the door
I have some friends in New York.

For negatives we can use a/an for singular nouns or any for plurals.

I don't have a dog.
There aren't any seats.

uncountable nouns

for positive sentence: some
for negative sentence: any

question

1. In question we use a/an, any or how many with countable nouns.
2. We use any or how much with uncountable nouns.
3. but we use some when we are offering something or asking for something.
4. We also use some in question when we think the answer will be 'yes'