I'm solving English grammar exam (MCQ) and one of the questions there is about the next sentence:
This car is my car, and that car is Tom's.
According to what I know the possessive s should come before the name rather than after him or in the end of sentence. Therefore it should be Tom's car rather than car Tom's. Then I'm not sure if what I see in the exam is just a mistake or it has explanation.
If you look a little more carefully at the question though, we aren't comparing the possessive structure Tom's car and car Tom's. The sentence actually says "that car is Tom's", and the is here makes all the difference.
Another thing about possessives is that we can also use them instead of a noun phrase to avoid repeating words, for example:
Whose coat is this? It’s my wife’s [coat]. > It’s my wife’s.
In your case the sentence states
This car is my car, and that car is Tom's [car].
...and the possessive allows us to remove the word car at the end of the sentence to give us...
that car is Tom's [car] > that car is Tom's.
And that car is Tom's [car].
Sometimes, we don't repeat the noun.
My house is on this street, Mary's [house] is over there.
In a possessive, you do not need to repeat the noun.
John's book is on the table. Where's Mary's [book]?
The noun is implied.
