Dave's ESL Cafe's Student Discussion Forums

[lfernando]

Hi.
Every now and then I am in doubt about the use of genitive case.
For example:
Book title or book's title
Movie stars's party or movie stars party
Is there any rule?
Thanks in advance,
Fernando

[redset]

We use the possessive (genitive) form to denote possession, a property or a relationship between two nouns:

Dave's ESL Cafe (Dave owns it)
The oven's temperature (a property of the oven)
His father (the father of a specific male person)

The apostrophe rules are pretty simple, but many native speakers get them wrong (you even see mistakes on professional signs all too often):

You can use possessive pronouns - my, her, his, your, its, whose, their, our

If your noun is plural and it ends in s, add an apostrophe - cats/cats', books/books', parties/parties'

Otherwise add 's - cat/cat's, book/book's, party/party's, grass/grass's, bass/bass's
(This applies to plurals not ending in s too - people/people's, women/women's)



I think that's only part of your question though - you're basically asking why we sometimes say book title but other times we use the possessive form? The possessive functions the way I explained at the beginning, and the possessive noun refers to something specific. If you say 'the book's title' you're talking about the title of a specific book. (If you use the indefinite article and say 'a book's title', you're basically saying 'imagine a book, it doesn't matter exactly what it is. Now, that specific book you're thinking of, we're talking about its title.')

In the phrase 'a book title' book functions more as an adjective, telling you what type of title we're talking about. 'Movie stars' party' would refer to a party thrown by (or for) some movie stars - it 'belongs' to them (as much as a party can belong to someone). 'Movie stars party', on the other hand, refers to a kind of party that relates to movie stars in general - perhaps people go in costume, dressed up as their favourite stars.

Some more examples:
baby's name - the name of some baby
baby name - a name you might call a baby (and possibly not an adult)

sports cars - fast, sporty cars
sport's cars - the cars used in a particular sport

window glass - the type of glass used in making windows
window's glass - the actual glass in a specific window

[lfernando]

Thanks very much for your help!