Possessive adjectives: mi, tu, su, nuestro and vuestro

Mis padres viven en Sevilla, pero nuestra casa está en Madrid.My parents live in Seville, but our house is in Madrid.

A possessive adjective says whose something or someone is: mi libro (my book), tu casa (your house), nuestros amigos (our friends). In Spanish it comes before the noun, it takes no article, and it agrees with the thing owned, not with the owner. The owner only decides which word you start from: mi, tu, su, nuestro, vuestro.

Quick shortcut: the owner picks the word (yo → mi, tú → tu, nosotros → nuestro…), and the thing owned picks the ending: -s for plural (mis libros), and for nuestro and vuestro also -o/-a for gender (nuestra casa). Spanish uses the same pair of forms for his, her, its, your (formal) and their: su / sus.

The forms

• mi, tu, su have only two forms: singular and plural. They don't change for gender: mi hermano and mi hermana both use mi.
• nuestro and vuestro have four forms, like an adjective ending in -o: nuestro amigo, nuestra amiga, nuestros amigos, nuestras amigas. See adjective agreement for the same pattern.
• vuestro goes with vosotros, which is mostly used in Spain. In most of Latin America, ustedes is the "you (plural)" form, so the possessive is su: ustedes y sus hijos.
• People who address each other with vos use tu/tus for the possessive: Vos tenés tu libro. (You have your book.)

The thing owned decides the ending, not the owner

The owner decides which word you start from (mi, tu, su…), but the ending follows the noun: its number always, and its gender for nuestro and vuestro. The owner's own gender never matters. So a woman and a man both say mi casa, and Ana (a woman) still says su libro, not "sua":

• Ana tiene su libro. (Ana has her book.)
• Ana tiene sus libros. (Ana has her books.)
• Carlos y Ana venden su casa. (Carlos and Ana are selling their house.)
• Carlos y Ana venden sus casas. (Carlos and Ana are selling their houses.)

In the last pair, the owners are the same two people, but the number of houses changes the word: su or sus. The same logic gives nuestra casa (one feminine house) but nuestros libros (several masculine books), even if the people who say it are all women.

No article, and the possessive comes first

The possessive takes the place of the article: el libro → mi libro. In standard Spanish the possessive adjective before a noun takes no article: ✅ mi casa, never ❌ la mi casa.

• Mi casa es pequeña. (My house is small.)
• ¿Dónde está tu móvil? (Where is your phone?)
• Mi casa nueva es pequeña. (My new house is small.) The possessive comes first, then the noun, then the usual adjective after it. See adjective position for where adjectives go.

Later you'll meet the stressed possessives (el mío, un amigo mío), which come after the noun or stand alone; they are a separate lesson, and everything here is about the short forms before the noun.

With parts of the body and clothing, Spanish often uses the definite article rather than a possessive (Me lavo las manos); see definite articles.

su: his, her, your, their

su and sus cover many owners at once: su casa can be his, her, its, your (with usted), or their house. Most of the time the situation makes it clear. When it doesn't, Spanish uses de + the owner after the noun:

When the owner is a name or a noun, de is the ordinary way to say it: el libro de Ana, la casa de mis padres, not "Ana su libro".

su is also the possessive for usted: ¿Es su coche, señora Pérez? (Is it your car, Mrs. Pérez?) With a friend you'd use tu: ¿Es tu coche, Marta? The choice follows the same tú / usted choice as in the address forms lesson.

Careful with the accent: tu / tú, mi / mí

Two of these words have a look-alike with a written accent, and they are different words:

• tu (possessive, no accent) vs tú (the subject pronoun "you"): Tú tienes tu libro. (You have your book.)
• mi (possessive, no accent) vs mí (the pronoun "me" after a preposition): Es para mí, no para mi hermano. (It's for me, not for my brother.)

See subject pronouns for tú.

Common mistakes

• ❌ la mi casa → ✅ mi casa (the possessive replaces the article)
• ❌ Ana tiene sus libro. → ✅ Ana tiene su libro. (one book, so the singular su; the possessive matches the thing owned)
• ❌ Mi amigas son simpáticas. → ✅ Mis amigas son simpáticas. (several friends, so mis)
• ❌ nuestro casa → ✅ nuestra casa (nuestro and vuestro also match gender: casa is feminine)
• ❌ Tú casa es grande. → ✅ Tu casa es grande. (the possessive has no accent; tú with an accent is the pronoun "you")

Quick check

Which possessive completes each sentence?

1. ___ casa es grande. (my)
2. Carlos y Ana viven con ___ padres. (their)
3. ¿Dónde está ___ coche, señora Pérez? (your, formal)
4. Somos hermanos, y ___ madre se llama Rosa. (our)
5. Tú tienes ___ libros. (your)
6. How can you make su hijo clearly mean "her son"?

Key takeaways

• A possessive adjective goes before the noun and replaces the article: mi casa, not la mi casa.
• The owner picks the word (mi, tu, su, nuestro, vuestro); the thing owned picks the ending. mi, tu, su add -s for plural: mis libros. nuestro and vuestro match gender and number: nuestra casa, nuestros libros.
• su/sus can mean his, her, its, your (formal) or their. When it isn't clear, use de él / de ella / de usted / de ellos / de ustedes after the noun: la casa de ella.
• With a name or noun as the owner, de is the usual way: el libro de Ana.
• Spelling matters: tu (possessive) vs tú (you), mi (possessive) vs mí (me, after a preposition).
• vuestro goes with vosotros (mostly Spain); ustedes takes su.