One simple question:
How come we say "Alice's book" but "car door". Why don't we say "car's door"?
Thanks in advance.
I can't give an example because I don't know the rule and I don't remember whether I've seen "car's door" or not.
The problem is that I don't know when we should use " 's " and when not. Could you please explain it with your own examples?
The best way I can explain it is simply to say that the door doesn't literally "belong" to the car. A car is an inanimate object. It cannot own or possess anything, so nothing can belong to it.
Alice's book is a book which literally belongs to Alice.
The car door is simply a door which happens to be attached to a car. It is the door of a car, not a door which belongs to a car.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
What about this context?
Compressed in the zip file, you’ll see the original course syllabuses which are downloaded from the universities’ official websites. Reference books are mentioned in each university’s “.pdf” file.
Could you please correct my mistakes and explain why you have done so?
I would just say pdf file- without the dot or the inverted commas.