what is it?
Cuyo is a relative possessive pronoun equivalent to English «whose». It links a noun (the antecedent) to something that belongs to or is associated with it, functioning like a relative pronoun and a possessive adjective at the same time. Unlike most relative pronouns, cuyo agrees in gender and number with the noun it precedes — the thing possessed — not with the antecedent (the possessor). It is most common in written and formal Spanish; in everyday speech, speakers typically use de quien or del que / de la que instead.
when to use it
Possession or close association in a relative clause. Use cuyo whenever the relative clause expresses that something belongs to, or is closely linked to, the antecedent: un escritor cuyas obras son famosas (a writer whose works are famous).
Formal and written registers. Cuyo is the standard choice in journalism, academic writing, and literature. In informal speech, de quien (for people) or del que / de la que / de los que / de las que (for things or people) are common alternatives.
Both restrictive and non-restrictive clauses. Cuyo works in both types: el edificio cuya fachada fue restaurada (restrictive) and la empresa, cuyo director dimitió ayer, (non-restrictive, set off by commas).
Never as a question word. Cuyo is exclusively a relative pronoun. To ask «whose?» in a question, use ¿De quién…?.
formation
Cuyo behaves like a possessive adjective: it immediately precedes the possessed noun and agrees with it in gender and number. The antecedent (the possessor) has no effect on the form chosen.
| possessed noun | form of cuyo | example |
|---|---|---|
| masculine singular | cuyo | el autor cuyo libro… |
| feminine singular | cuya | la autora cuya novela… |
| masculine plural | cuyos | el autor cuyos libros… |
| feminine plural | cuyas | la autora cuyas novelas… |
The structure is always: antecedent + cuyo/a/os/as + possessed noun. No article appears between cuyo and the possessed noun: el país cuya capital es Madrid, not *el país cuya la capital.
examples in context
common pitfalls
Calquing English with que + possessive. A direct translation of «the author that his novels…» produces the ungrammatical *el autor que sus novelas…. Spanish has no equivalent of this construction; the only standard option is el autor cuyas novelas….
Agreeing cuyo with the possessor instead of the possessed noun. Because the antecedent is the most recent noun, learners often match cuyo to it. This gives *un autor cuyo novelas (masculine, matching autor) instead of the correct un autor cuyas novelas (feminine plural, matching novelas). Always look forward to the possessed noun, not back to the antecedent.
Using cuyo as an interrogative. Cuyo is never a question word. *¿Cuyo libro es este? is ungrammatical. Use ¿De quién es este libro? instead.
In informal spoken Spanish, cuyo is often avoided entirely. If you hear un autor del que conozco sus novelas or un autor de quien conozco las novelas, these are acceptable spoken alternatives — but in writing, cuyo is the preferred and more precise form.
Three sentences, graded here. Nothing is saved and no account is needed.
El volcán ___ erupciones han devastado la región varias veces sigue siendo uno de los más activos del mundo.
Fill in the blank with the correct form of cuyo.