Question about The A An

[Nader75]

"The" used with noncountable nouns
"A , An " used with Countable nouns
my question is when I must't to use the, a, an
I mean like this :
red flowers

[Casiopea]

Use "the" with singular or plural specific nouns, and "a/an" with singular non-specific nouns, like this,

singular specific count noun: the cow
plural specific count noun: the cows
specific non-count noun: the milk
singular non-specific count noun: a cow, an owl

[Nader75]

how to distinguish between the specific noun and unspecific noun

[Tdol]

If it's specific, you can tell which things or who you are referring to. If I say 'students work hard', I am talking in general, but if I say 'the students in this forum', then I am being specific and not talking in general.

[Nader75]

I got it
thank you