What is the Hebrew word for it?

Answer 1

There is no Hebrew word for it. It would depend on context of the sentence. For example:

• kar (קר) = it is cold, literally "cold"
  
• hu tov (הוא טוב) = it is good, he is good
  
• ani ohev et zeh (אני אוהב את זה) = I love it, I love this
  

Note: the Stephen King book "It" is translated into Hebrew as Zeh (זה), which means "this".

Answer 2

If you are asking how to say "It's" in Hebrew, it depends entirely on context. You would need to provide the entire sentence.

Answer 3

There is no Hebrew word that equates to "it's". It depends on context:

It's cold = kar li (literally "cold to me").

It's a boy = zeh yeled (literally "this (is a) boy")