The possessive case of nouns has basic concepts and usages
1. What is possessive
What is possessive? To put it simply, possessive case means belonging, that is, something is owned by someone. As you know, Chinese has no possessive case, and it is usually OK to add the word "de" to indicate that something is owned by someone. For example, when we say "Jim's computer", it means that the computer is owned by Jim, and the ownership here is reflected by the word "de". English possessive construction is similar to that in Chinese. It is usually formed by adding -'s at the end of a noun. For example, this student means "this student". To express "this student's homework", we say this student's home work, where -'s is roughly equivalent to the Chinese word "de".
2. Composition of possessive case
(1) For singular nouns: a singular noun should form the possessive case, we usually add an apostrophe and the letter s after it. For example:
You should never ask a lady's age.
Bill Smith's surname is Smith.
Even if the singular noun ends with the letter s. For example:
He was late for work, so he stole past his boss's office.
Although the boss in the sentence ends with an s, its possessive case should still be added with -'s. For another example, the actress's beauty means "beauty of an actress", where actress means "actress". Although it ends with "s", it still needs to add -'s.
(2) For plural nouns, we should distinguish between two situations, that is, whether it has the suffix - s or not, and if it has the suffix - s, we just need to add an apostrophe after it. For example:
He goes to the Teachers' College.
I'll take two weeks' holiday.
However, if the plural noun itself does not have the suffix - s, its possessive case is still formed in the form of -'s. For example:
I can't remember people's names.
(3) For names with the suffix - s: the possessive case can either add the suffix -'s or just an apostrophe. For example:
Dickens' Novels Charles' Job
3. Shared ownership
If we want to show that two or more people share something, we need to use the shared possessive case. At this time, we just need to change the last noun among several paratactic nouns to the possessive case. For example:
This is Black and Smith's company.
Of course, if you want to express the things of several people, you should add -'s after the coordinate nouns. Compare:
These are Tom's and Jim's rooms.
This is Tom and Jim's room.
4. "of+noun" structure
Similar to the usage of the possessive case of nouns, the "of+noun" structure is also a possessive case in a sense, and in general, the possessive case formed by -'s can be converted into the "of+noun" structure. For example:
I heard a man's voice.=I heard the voice of a man.
Generally speaking, -'s possessive case is mainly used for living nouns, while of possessive case can be used for living people or things, and also for inanimate things. Therefore, when used for inanimate nouns, the "of+noun" structure is usually used only. For example:
Our school is on the left of the road.
You'll find the answers at the back of the book.
Note that the road's left or the book's back cannot be said in English.
However, for some nouns indicating time, country, city, etc., although they have no life, they can also use -'s to form possessive case. For example:
Did you see yesterday’s film? Did you see the film yesterday?
Today's weather is worse than yesterday's.
5. Dual Possession
The so-called double possessive case refers to the combination of -'s possessive case and of structure. For example:
She's a friend of my father's.
Comparing the following expressions, they have different meanings when using the double possessive case and the of possessive case:
This is a photo of Mary's.
This is a photo of Mary.
