Subjunctive in Adjective Clauses with unknown precedent

Subjunctive in Spanish

SOURCE: http://www.bowdoin.edu/~eyepes/newgr/ats/47.htm

I do agree with bowndoin.edu when they say that ….

The subjunctive is used in an adjective clause when the antecedent is someone or something whose existence is unknown, hypothetical or uncertain from the point of view of the speaker

Let' see some examples:
Necesito que una profesora me expliqueI need that a teacher explains this to me
No hay películas que me llamen la atención There are no movies that catch my attention
¿Hay alguien que pueda contarme lo que paso?Is there anyone who can tell me what has happened?
Elije la película que más te guste.Pick the movie that you like the best.
Busco un novio que pueda valorarme. I look for a boyfriend that can value me.
(no personal a: it's not a definite person)

I do agree with the author of this webpage http://www.bowdoin.edu/~eyepes/newgr/ats/47.htm that…

If the antecedent is known to exist, the indicative is used:
Busco al secretario que sabe francésI am looking for the secretary who knows French.
Necesita el libro que explica esto.She needs the book that explains this.
Hay novelas que me interesan.There are some novels that interest me.
Aquí hay alguien que necesita ayuda.There’s someone who needs assistance here.
Escojo las clases que más me gustan.I pick those classes I like best (after checking them out

When the antecedent is not mentioned, adjective clauses are introduced by lo que (what...):
Haz/hacé (voseo) lo que quieras.Do what(ever) you (may) want.
(Tu) Haces exactamente lo que quieresYou do exactly what you want. (you know what it is)
No me importa lo que digan.I do not care what they (may) say. (whatever it is)
No me importa lo que dicen.I do not care about what they're saying. (I know what it is)

SOURCE: http://www.bowdoin.edu/~eyepes/newgr/ats/47.htm

Note that, when the reference is unknown (subjunctive needed), English uses different ways to convey the vagueness of the antecedent, often translating lo que as “anything that, whatever”.

  • Something indefinite and with lack of clearness is often stressed by repeating the verb in subjunctive.

For example:

  • Digan lo que digan: What (whatever) they say
  • Hagas lo que hagas: no matter what (whatever) you do