I do know that it is in writing part but I think that it is important in writhing.
Sometime we might have trouble with it ..
so what are the differences between these sentences:
1 John has a new computer.
2 The new computer is John's.
3 This new computer is to John.
Have fun

Yes they are completely different among the three! It is easier understand by taking a look or the clues bellow:
1 John has a new computer. Mean that the speaker is a bit surprised with what Jonh has because last time never does Jonh consist such thing ( It's possible that he himself buy or someone else buys for him).
2 The new computer is John's. It should be answer the question " Whose this new computer is it". It infers to find the owner of the computer.
3 This new computer is to John. It suggests that someone buy Jonh a new computer. For example:
Long: Hey Seangheng, you are just back from Japan, do you have anything for me and Jonh?
Seangheng: Yes I do! This radio is for you!
Long: What about this new computer?
Seangheng: It is/ the new computer is for ( or to) Jonh!
That's it!!
Kimlong