Interested in Language
"It's nothing to do with you" is an expression I come across a good deal when watching films and soap operas in English. Its meaning, if I'm not mistaken, is equal to "It's none of your business". What I don't yet grasp is what "It's" stands for. My instinct tells me that it's the short form of "It has" because we can say something like: "I have nothing to do with the robbery". But it still troubles me somehow because normally we either say "He has..." or "He's got..." in Br.E. I don't think anyone would ever say "He's a car." to mean that "He's got a car." That's why if "It's" is the short form of "It has", it will be really weird to me. Is it an exception of using "It's" as "It has" or are there other instances in which this short form may be used? Thanks for any explanation!
Yesterday, I read a book that has a sentence like this: "The central point of that passage in my review of The Selfish gene was to do with the kind of slippage that can occur when language is used loosely."
So, it may be logical to infer that "It's nothing to do with you" is actually the short form for "It is nothing to do with you". Like I said, I've never seen the use of "It's" for "It has".
***Neither a teacher nor a native speaker.***
It's okay to use "it's" to express "it has".
However, it's not good for the sentence you posted.
Some examples where it's fully okay:
It's good. -> It is good.
It's been a while. -> It has been a while.
It's my car. -> It is my car.
He's not finished his homework yet. -> He has not finished his homework yet.
In all these sentences it is clearly visible what the full version of "it's" (or "he's") is.
You can't say:
It has good.
It is been a while.
It has my car. (Theoretically possible, but probably a rare case.)
He is not finished his homework yet.
Whenever it's unclear whether it is "it has" or "it is", like "It's nothing to do with you.", I highly suggest you not to use the short version!