Cuyo in Relative Clauses

The relative cuyo means "whose" and is used to show possession within a relative clause. It belongs to the more formal end of Spanish and appears more often in writing than in everyday speech, but any serious student should learn it. Its distinctive feature is that it agrees with the thing possessed, not with the possessor.

The Four Forms

Cuyo behaves like an adjective. It has four forms that agree in gender and number with the noun it modifies.

FormUse
cuyomasculine singular
cuyafeminine singular
cuyosmasculine plural
cuyasfeminine plural

Agreement with the Thing Possessed

This is the single most important rule: cuyo agrees with the thing possessed, not with the owner. English speakers often get this wrong because in English "whose" doesn't change form. In Spanish, it does.

El hombre cuya esposa conoces vive en Bogotá.

The man whose wife you know lives in Bogotá.

The man is masculine, but cuya is feminine because it agrees with esposa (feminine), the thing possessed. The owner's gender is irrelevant.

La casa cuyos dueños viajaron está vacía.

The house whose owners traveled is empty.

Here cuyos is masculine plural because it agrees with dueños, even though casa (the owner in the sentence's structure) is feminine singular.

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To pick the right form of cuyo, look at the noun that comes immediately after it, not the noun it refers back to. That noun decides gender and number.

No Article Between Cuyo and the Noun

Unlike English "whose," cuyo attaches directly to the possessed noun with no definite article in between. Saying cuyo el libro or cuya la esposa is ungrammatical.

El autor cuyo libro gané es uruguayo.

The author whose book I won is Uruguayan.

Notice there is no el between cuyo and libro.

Formal and Written Register

Cuyo belongs mostly to formal and written Spanish. In conversation, Latin American speakers often avoid it and restructure the sentence with de or que.

Formal with cuyoConversational alternative
El chico cuya madre es doctora...El chico que su mamá es doctora...
La empresa cuyos empleados protestaron...La empresa que sus empleados protestaron...

The colloquial que su forms are considered incorrect in formal writing, but they are extremely common in speech. If you are writing an essay or article, cuyo is the right choice.

Cuyo with Prepositions

Cuyo can be introduced by a preposition, and the preposition comes before cuyo. This creates elegant sentences that would otherwise be clumsy.

El escritor en cuya casa nos reunimos es famoso.

The writer in whose house we gathered is famous.

Los niños a cuyos padres llamamos ya están bien.

The children whose parents we called are already well.

Cuyo Is Never a Question Word

Do not confuse relative cuyo with anything related to ¿cuyo? as a question word—it doesn't exist in that role in modern Spanish. Asking "whose" uses ¿de quién? instead.

¿De quién es ese carro?

Whose car is that?

Ese es el hombre cuyo carro gané en el sorteo.

That is the man whose car I won in the raffle.

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If you are speaking informally and cuyo feels stiff, rephrase the sentence. You can often use two short sentences: Ese señor tiene una esposa. Tú la conoces. Native speakers frequently split complex sentences this way to avoid cuyo.

For the broader picture of relative clauses, see Restrictive Relative Clauses and Non-Restrictive Relative Clauses.

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