1. Possessive Adjectives

2. Possessive adjectives in English are as follows:
my our
your your
his, her, their
its

3. Possessive adjectives in Spanish: mi nuestro tu vuestro su su
Because these are possessive adjectives, they change just like all other adjectives:
mi casa, mis casas nuestro libro, nuestros libros, nuestra casa, nuestras casas
tu casa, tus casas vuestro libro, vuestros libros, vuestra casa, vuestras casas
su casa, sus casas su casa, sus casas
Mi, tu, and su have just singular and plural forms, because they don’t end with an –o. Nuestro and vuestro, which do end with an –o, have four forms: masculine singular, feminine singular, masculine plural, feminine plural.

4. “Sus” can mean “his,” “her,” “its,” “their,” or “your.”
mi nuestro
tu vuestro
su su
You may be bothered by the fact that “su” is in two places. “Su” can mean “his,” “her,” “its,” “their,” or “your.”
“Sus” can mean “his,” “her,” “its,” “their,” or “your.”
You use “su” when the noun is singular:
su primo = his cousin, her cousin, your cousin, their cousin
sus primos = his primos, her primos, your primos, their primos
The only thing the –s on the end of the “su” tells you is that the noun is plural. It tells you absolutely nothing about whether the word means his, their, etc.

5. What you can do if it’s not clear whether “su” means “his,” “her,” etc
What you can do if it’s not clear whether “su” means “his,” “her,” etc., is this:
su libro = el libro de él
su libro = el libro de ella
In other words, you can say “the book of him” rather than “his book.

6. That brings us to another point: there are no apostrophes in Spanish
That brings us to another point: there are no apostrophes in Spanish. The way you say, “Juan’s father,” is “the father of Juan”:
El padre de Juan

7. Práctica
Mi madre ¿Dónde está tu padre? Él es su primo. Nuestra familia es grande. Su hermanastro es guapo.
My mother Where is your father? He is her cousin. Our family is big. Their step-brother is good looking.

8. Click here to go to your homework.