Subjunctive with indefinite or non-existent antecedents

Busco un piso que tenga balcón.I'm looking for a flat that has a balcony.

A relative clause with que describes a person or thing, and Spanish picks the mood by asking whether that person or thing is known and real (indicative) or unspecified or possibly non-existent (subjunctive). If you have a particular flat in mind, you say tiene. If any flat with a balcony would do, and you do not even know whether one exists, you say tenga.

Quick shortcut: a relative clause describing something specific and real takes the indicative (un piso que tiene balcón, "a flat that has a balcony"). One describing something unspecified, wished for, or non-existent takes the subjunctive (un piso que tenga balcón, no hay ningún piso que tenga balcón). The noun being described is called the antecedent.

Specific or not: the same sentence, two meanings

The mood in the relative clause tells the listener which kind of thing you mean:

• Busco un piso que tiene balcón. (There is one flat I know about, and it has a balcony.)
• Busco un piso que tenga balcón. (I want a flat with a balcony. Any one will do, and I don't know if I'll find one.)
• Tengo una amiga que habla ruso. (I have a friend who speaks Russian. She exists.)
• Necesito una amiga que hable ruso. (I need a friend who speaks Russian. I don't have one yet.)

Verbs of wanting, needing, looking for and asking for (buscar, necesitar, querer, preferir, pedir) very often introduce this kind of unspecified antecedent, since the thing wanted may not exist or may not be found. They don't force the subjunctive on their own, though. Busco el libro que escribió mi tío (a specific book) takes the indicative.

After buscar, a specific person takes the personal a, and an unspecified one tends not to: Busco a la secretaria que habla inglés (the one I know about) versus Busco una secretaria que hable inglés (any secretary who qualifies). The a is not a reliable signal on its own, though, and Busco a una secretaria que hable inglés is also heard. Alguien and nadie take it whenever they are the direct object (Busco a alguien que hable ruso), but not as subjects (Hay alguien que sabe arreglarlo). For the personal a, see the personal a.

Non-existent: no hay nadie que, no conozco a nadie que

When the main clause says that nobody or nothing of that kind exists, the relative clause is in the subjunctive, because there is nothing real for it to describe:

• No hay nadie que sepa arreglar esto. (There is nobody who knows how to fix this.)
• No conozco a nadie que hable ruso. (I don't know anyone who speaks Russian.)
• Aquí no hay nada que me guste. (There is nothing here that I like.)
• No existe ningún método que funcione siempre. (No method exists that always works.)

The affirmative counterpart takes the indicative, because now the thing does exist: Hay alguien que sabe arreglarlo. (There is someone who knows how to fix it.) Conozco a alguien que habla ruso. (I know someone who speaks Russian.) Words like alguien, nadie, algo, nada, ninguno are covered in indefinite pronouns and negative words.

Questions: you don't know the answer yet

In a question, the subjunctive shows that the speaker doesn't know whether such a person or thing exists, while the indicative suggests the speaker expects or assumes that one does:

• ¿Hay alguien que sepa arreglar esto? (Is there anyone who knows how to fix this?) The speaker has no idea.
• ¿Conoces a alguien que hable ruso? (Do you know anyone who speaks Russian?) A genuine open question.
• ¿Conoces a alguien que habla ruso? The speaker half expects a yes.

After a past main verb: the imperfect subjunctive

The usual rule for matching tenses applies here too. When the main verb is in the past or the conditional, the relative clause usually takes the imperfect subjunctive, for something simultaneous with or later than the main verb:

• Buscaba un piso que tuviera balcón. (I was looking for a flat that had a balcony.)
• Quería una secretaria que hablara inglés. (I wanted a secretary who spoke English.)
• No había nadie que lo supiera. (There was nobody who knew it.)
• Me gustaría vivir en una ciudad que estuviera cerca del mar. (I would like to live in a city that was near the sea.)

If the described situation comes before the main verb, the pluperfect subjunctive is used instead: No había nadie que lo hubiera visto. (There was nobody who had seen it.) See the pluperfect subjunctive. The forms of the imperfect are in the imperfect subjunctive; the -se forms (tuviese, hablase) are equally correct.

Open-ended: cualquier ... que and lo que quieras

The same logic applies to words that mean "any" or "whatever," because they point to something not yet identified:

• Cualquier persona que llegue tarde esperará fuera. (Anyone who arrives late will wait outside.)
• Llévate lo que quieras. (Take whatever you like.) The pronoun lo que is introduced in lo que.
• Hazlo como prefieras. (Do it however you prefer.)

Here the speaker leaves the choice open, so nothing in the clause is a settled fact.

Common mistakes

• ❌ No conozco a nadie que habla ruso. → ✅ No conozco a nadie que hable ruso. (after nadie or ninguno, nothing real is being described, so the subjunctive is used.)
• ❌ No hay nada que me gusta. → ✅ No hay nada que me guste. (same rule with nada.)
• ❌ No había nadie que lo sabía. → ✅ No había nadie que lo supiera. (a past main verb calls for a past subjunctive, here the imperfect.)

Quick check

1. Complete: Necesito un coche que ___ (ser) barato y fiable. (any car that qualifies)
2. Complete: Tengo un vecino que ___ (tocar) el violín. (a real neighbour)
3. Complete: No hay nadie en la oficina que ___ (saber) la respuesta.
4. Complete: Quería una casa que ___ (tener) jardín.
5. What is the difference between Busco a la profesora que habla alemán and Busco una profesora que hable alemán?

Key takeaways

• The mood in a relative clause depends on the antecedent: specific and real takes the indicative, unspecified or non-existent takes the subjunctive.
• Verbs of wanting, needing and looking for often introduce an unspecified antecedent (Busco un piso que tenga balcón), but they take the indicative when the thing is a particular one.
• After no hay nadie / nada / ningún and no conozco a nadie, the subjunctive is used because nothing real is being described. The affirmative (hay alguien que sabe) takes the indicative.
• In questions, the subjunctive shows the speaker doesn't know whether it exists, and the indicative suggests the speaker expects it does.
• After a past main verb, the relative clause usually uses the imperfect subjunctive (Buscaba un piso que tuviera balcón), or the pluperfect for an earlier situation (No había nadie que lo hubiera visto).
• Open-ended phrases such as cualquier ... que and lo que quieras take the subjunctive.