I hear lots of people say " What's that ? What's this ? Who's this? " but hardly hear people just say " What's it ? or Who's it? Does anyone know why ? Also , which is more correct way to say this sentence? " There is water and milk on the talbe. There are water and milk on the table." Why ?
I get the whole There is / There are thing wrong a lot when I speak. I almost never use There are when I should. For me it is because I haven't formed the whole sentence when I start off.
Still, I know the rule. Here's the test:
Instead of There is/are x …, invert the sentence to be x is/are there …
Whichever verb you pick for the inverted sentence is the correct one for the There is/are version.
So, for your example, I would say Water and milk are there on the table. As a result, the correct form would be There are water and milk on the table.
Regarding the contractions of subject and verb, I think it's just a matter of overall length and weight. These kinds of contractions — as opposed to the contration of verb with not — take place because the verb element is somewhat secondary to the meaning of the sentence, so it is no great loss to contract the verb with the subject. When the verb element is not secondary, we are unlikely to contract them with the subject.
You think he won't come, but I say he will come. (rather than he'll come.)
He'll come is more likely if you are contrasting the you/I rather than the won't/will. And some might say he'll not as opposed to he won't.
In a sentence like It is. we simply can't contract it to *It's. because each element is too significant.
You can say what's it going to take? Who's it going to help? but not simply Who's it? What's it? It's! I'm. You're?
But, oddly, the contraction of verb with not doesn't seem to follow that same pattern. You can say It isn't. but It is not. has a bit more force. The contraction of not seems to retain significant force.
And Whosit and Whatsit are words that can be used as nouns to stand in for random or unnamed people or things which, I think, goes along with the idea that the contraction is OK when it carries little weight.
Off topic here...but I now have a song from "The Little Mermaid" stuck in my head,
I've got whosits and whatsits galore
You want thingamabobs? I've got 20.
But who cares? No big deal.
I want mooooooooore
Word Nerd, when I first read this that song got stuck in my head too. You're not alone!!