Some is used in affirmative sentences with countable plural
nouns or uncountable nouns.Examples: There are some boys in the
park. There is some milk in the bottle.
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Any
Any is used in interrogative and negative sentences with
countable plural nouns or uncountable nouns.Examples:Are there any
books on the shelf? No there aren' t any.Is there any water in the
glass? No, there isn't any.
A / an
A is used with singular countable nouns.Example:There is a house
on the hill.An is used with singular countable nouns starting with
a vowel.Example:There is an apple on the plate.
