When you use "it" in a sentence, "it" is the subject. But it usually refers to something else, or so is my understanding.
In certain sentences it is obvious what it is referring to, but in other more "abstract"/"generic" is not and I find myself a bit lost.
For example, the sentence:
The cat was yellow. It reminded me of my pillow.
In this sentence "it" is obviously the cat. However in sentences like:
It was midnight
What does It stand for in that sentence? Is it the night? the time? Is there some kind of grammar rule that apply for this kind of sentences?
I was trying to help my nephew understand it better, he is studying English as a second language, but I found I was almost as lost as him. I understand the second sentence, but I don't know how to explain him how it works so he can understand it too.