Subjunctive in Adjective Clauses / El subjuntivo en cláusulas adjetivas

An adjective clause is a group of words –containing a verb– that 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. No hay novelas que me interesen. ¿Hay alguien que tenga sugerencias? Escoge la clase que más te guste. Busco un secretario que sepa francés. (no personal a: it's not a definite person)

I need a (some) book that explains this. There are no novels that may interest me. Is there anyone who may have any suggestions? Choose whichever class you like best. I am looking for a secretary who knows French.

• If the antecedent is known to exist, the indicative is used:

Busco al secretario que sabe francés. Necesita el libro que explica esto. Hay novelas que me interesan. Aquí hay alguien que necesita ayuda. Escojo las clases que más me gustan.

I am looking for the secretary who knows French. She needs the book that explains this. There are some novels that interest me. There’s someone who needs assistance here. 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 lo que quieras. Haces exactamente lo que quieres.	Do what(ever) you (may) want. You do exactly what you want. (you know what it is)
No me importa lo que digan. No me importa lo que dicen.	I do not care what they (may) say. (whatever it is) I do not care about what they're saying. (I know what it is)

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".

• Indefiniteness or lack of restriction is often stressed by repeating the verb in subjunctive.

digan lo que digan hagas lo que hagas

no matter what (whatever) they say no matter what (whatever) you do

Ejercicio:

1. Tengo éxito gracias a la gente que me (apoya/apoye).

   2. Voy a tener éxito si encuentro gente que me (apoya/apoye).

   3. Necesitamos empleados que (conocen/conozcan) la tecnología.

   4. Tenemos empleados que (conocen/conozcan) la tecnología.

   5. Busca una persona que te (puede / pueda) ayudar.

   6. Conozco a una persona que te (puede / pueda) ayudar.

   7. ¿Hay algún restaurante que (sirve / sirva) comida hispana?

   8. Queremos un restaurante que (sirve / sirva) comida hispana.

   9. Queremos la casa que (tiene/ tenga) vista al mar.

   10. Vivimos en una casa que (tiene/ tenga) vista al mar.

para mÁs ejercicios y la pÁgina original pincha aquí

the Present Subjunctive in Noun Clauses

A noun clause is a group of words (containing a verb), which is the subject or object of the main clause verb:In the sentence "I demand that he be here", the words "that he be here" are the noun clause, object of the main verb "demand".

The subjunctive is used in a noun clause when the main verb expresses
influence (an indirect command), emotion, doubt, disbelief or denial.
Exijo que esté aquí. I demand that he be here.

• Spanish frequently uses the present subjunctive with a future meaning (the future subjunctive is no longer used):
Me alegra que haya clase mañana. I'm glad (that) there will be class tomorrow.
Note that the relative que cannot be ommitted as English often omits “that”.

A. INFLUENCE: After verbs expressing want, desire, hope, request, insistence, command, suggestion, etc., what is in the clause is like a command and must be in the subjunctive:

Espero que vayas. Te digo que lo hagas ahora. Insisto en que esté presente.

I expect you to go. Im telling you to do it now. I insist that he be present.

• English frequently uses a phrase with the infinitive to express indirect commands: "I want him to do it" etc. Spanish must use the subjunctive: Quiero que lo haga.

• If the verb in the main clause simply
reports a situation (usually with decir) perceived as real, use the indicative: Te digo que está lloviendo.I tell you that it is raining.

B. EMOTION: When the main verb expresses any
subjective attitudes (sorrow, surprise, anger, indifference, concern, hope), the verb in the noun clause must be in the
subjunctive:

Siento que no vayas. Me sorprende que Ud. no lo sepa. Es triste que no haga sol.

I am sorry that you're not going. It surprises me that you do not know it. It's sad it isn't sunny.

• With verbs of influence and emotion, use the infinitive if there is only one subject::

Quiero ir. Espero ir. Siento molestarte. Estamos felices de trabajar aquí.	I want to go. I hope to go. I'm sorry to disturb you. We're glad we work here.
BUT: Estamos felices de que trabajes aquí.	We're glad that you work here.

C. DOUBT, DISBELIEF or DENIAL: When the main verb expresses uncertainty or denies a previous statement, the verb in the noun clause should be in the subjunctive:

Doubt or Disbelief:	Dudo/No creo que vaya. No es posible que sea verdad. Es increíble que te vayas.	I doubt/I don't think I'm going. It's not possible that it is true. It's hard to believe you're leaving.
Denial:	No digo que sea tonto. Es falso que me moleste el ruido. No es cierto que haya marcianos.	I am not saying (that) he is stupid. It is false that noise disturbs me. It's not true that there are Martians.

• In general, creer, no dudar, ser verdad, and other expressions of conviction are not followed by the subjunctive, while no creer, dudar, no ser cierto, etc., are:
Creo que va a llover but No creo que llueva
In questions, the clause may not involve a subjunctive, depending on the doubt in the mind of the speaker:
¿Crees que va a llover? or ¿Crees que llueva?

Ojalá, whose form is invariable, meant originally something like "O to Allah" in Arabic and it is used to express a general wish or hope. It is always followed by the subjunctive:

Ojalá (que) vengan mañana. Ojalá no llueva.

I hope they come tomorrow. Hopefully it won't rain.

Ojalá may be used with or without que with no change in meaning.
See www.colby.edu/~bknelson/SLC/ojala/cancion.html for a good practice on ojalá in a Dominican song.

 tal vez, quizás, quizá, which all mean perhaps, are followed by the subjunctive if the speaker wants to convey a considerable degree of doubt (que is not used here):

Tal vez llegue pronto. Quizás vamos al cine.

Perhaps he will arrive soon. (probably not) Maybe we'll go to the movies. (very possible)

Más ejercicios y la página original en el enlace.

The Forms of the Present Subjunctive / Las formas del presente del subjuntivo

	present indicative	PRESENT SUBJUNCTIVE
ayudar poner seguir	yo ayud-ø   yo pong-ø   yo sig-ø	ayude ayudes ayude ayudemos ayudéis ayuden ponga pongas ponga pongamos pongáis pongan siga sigas siga sigamos sigáis sigan

In order to form the present subjunctive, use the first person singular of the present indicative –the yo form–, remove the -o, and add endings in -e for -ar verbs, and endings in -a for -er and -ir verbs. This change of vowel may involve some spelling changes:
pag-ø  pague busc-ø  busque empiez-ø  empiece

• Stem-changing verbs in -ar and -er change their stems in the same way and in the same cases as in the present indicative:

piense vuelva

pienses vuelvas

piense vuelva

pensemos volvamos

penséis volváis

piensen vuelvan

• Stem-changing verbs in -ir, whatever the change that occurs in the present indicative, change the stem of thenosotros and vosotros forms of the present subjunctive from e to i and from o to u. (see complete rules.)

muera sienta pida

mueras sientas pidas

muera sienta pida

muramos sintamos pidamos

muráis sintáis pidáis

mueran sientan pidan

Only six verbs do not follow the rules above to form the present subjunctive:

ir  →  vaya, vayas, vaya, vayamos, vayáis vayan ser  →  sea seas sea seamos seáis sean estar  →  esté estés esté estemos estéis estén saber  →  sepa sepas sepa sepamos sepáis sepan haber  →  haya hayas haya hayamos hayáis hayan (subjunctive for hay) dar  →  dé des dé demos deis den

Subjunctive?

All the verbs we have studied so far have been in the Indicative Mood because they indicate states or actions that are presented as factual. The Subjunctive Mood is used, mostly in dependent clauses, after verbs that suggest non-factual events, such as indirect commands, doubts, subjective perception, etc. Compare the following two groups of sentences:

Presented as factual (indicative):	Desired, doubted (subjunctive):
I insist that he is here. Insisto en que está aquí.	I insist that he be here. Insisto en que esté aquí.
I believe he did it. Creo que lo hizo.	I demand that he do it. Exijo que lo haga.
I know he is here. Sé que está aquí.	I doubt he'll be here. Dudo que esté aquí.

práctica online y página original aquí.