Subjunctive in Adjective Clauses

Subjunctive in Adjective Clauses

An adjective clause is a group of words –containing a verb– which tells something about a noun. This noun to which the clause refers is called its antecedent:
I admire those women who stand for their rights.
antecedent adjective clause

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:
Necesito un libro que me explique esto. I need a (some) book that explains this.
No hay novelas que me interesen. There are no novels that may interest me.
¿Hay alguien que tenga sugerencias? Is there anyone who may have any suggestions?
Escoge la clase que más te guste. Choose whichever class you like best.
Busco un secretario que sepa francés.
I am looking for a secretary who knows French.
(no personal a: it's not a definite person)

• If the antecedent is known to exist, the indicative is used:
Busco al secretario que sabe francés. I 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 choose those classes I like best (after checking them out).
• When the antecedent is not mentioned, adjective clauses are introduced by lo que (what...). Use the subjunctive when the reference is hypothetical or unknown (often in the future):
Haz lo que quieras. Do what(ever) you (may) want.
No me importa lo que digan. I do not care what they (may) say. (whatever it is)
• When lo que refers to something definite, it is followed by the indicative:
Haces exactamente lo que quieres. You do exactly what (you know) you want.
No me importa lo que dicen. I do not care about what they're saying (I know what).
• Indefiniteness or lack of restriction is often stressed by repeating the verb in subjunctive:
digan lo que digan no matter what (whatever) they say
hagas lo que hagas no matter what (whatever) you do