The document discusses rules for using the genitive case in English. It explains that to indicate possession with a singular noun, add an apostrophe and s ('s). For plural nouns ending in s, add only an apostrophe. For irregular plural nouns like children and men, add 's. When multiple nouns indicate possession, only add 's to the last noun.

1. GENITIVE CASE

2. Singular
Add ------- 's
Examples:
The brother of Angel goes surfing
Angel ‘s brother goes surfing
The name of my teacher is Angel
My teacher's name is Angel

3. Plural
Add the apostrophe ' to regular plural forms:
Examples:
The room of the girls is very nice.
The girls' room is very nice.
The car of the Smiths is black
The Smiths' car is black.

4. Plural
Add 's to irregular plural forms:
Examples:
The children's books are over there.
Men's clothes are on the third floor.

5. Plural
If there are multiple nouns, add an 's only to the last noun:
Peter and John's mother is a teacher.