When does the relative clause take the subjuntivo?
A relative clause describes the antecedent, the noun before que. English writes the same words whether or not the antecedent exists. In Spanish the mood depends on whether it exists and whether you can point at it.
One letter, two different worlds
Tengo un amigo que habla alemán.
I have a friend who speaks German.
the friend exists – you could name him
Busco un amigo que hable alemán.
I'm looking for a friend who speaks German.
no such friend yet – you are describing a wish
Busco a la secretaria que habla inglés.
I'm looking for the secretary who speaks English.
a specific person you know
Busco una secretaria que hable inglés.
I'm looking for a secretary who speaks English.
any secretary who fits
The usual triggers
The subjuntivo appears whenever it is open whether the antecedent exists at all. Three cases are the most common.
Looking for, wanting, asking
After buscar, necesitar and querer, or in questions like ¿hay algún...?, the antecedent has not been found yet.
Busco un apartamento que tenga balcón.
I'm looking for a flat with a balcony.
Necesito a alguien que me ayude.
I need someone to help me.
¿Hay algún hotel que tenga piscina?
Is there a hotel that has a pool?
Non-existent
After no hay nadie, no existe ningún or no conozco a nadie, the antecedent does not exist.
No hay nadie que lo sepa.
There is nobody who knows.
No conozco a nadie que hable japonés.
I don't know anyone who speaks Japanese.
Open and unspecified
With lo que and quien, which have no fixed antecedent, it stays open what or who is meant.
Haré lo que sea necesario.
I'll do whatever is necessary.
Quien quiera venir, que venga.
Whoever wants to come, let them come.
