Ok, according to the grammar, we use "The" for definite noun.
But my question is:
When is a noun definite?
See this conversation:
A: I saw a big rat in my back yard last night.
B: How big is THE rat?
Why does "B" use "THE" when he has never seen that rat?
So, we can use "THE" even though we have never seen or known it before, can't we?
See other conversation:
A: Let go to the zoo
B: I want to see THE elephants
Does this above conversation make sense? So, we use "THE" because we identified THE elephants in the zoo, don't we?
But see other conversation:
A: I want to see elephants
B: Let go to the zoo
The plural "elephants" without any article in the above conversation mentioned elephants in general, didn't it?
I am so confused! When is a noun definite?