What is the subjunctive form in spanish, when do you use it?

Answer 1

In grammar, the subjunctive mood (sometimes referred to as the conjunctive mood) is a verb mood that exists in many languages. It typically expresses wishes, commands (in subordinate clauses), emotion, possibility, judgement, necessity, and statements that are contrary to fact at present. The details of subjunctive use vary from language to language.
In Spanish, the subjunctive (subjuntivo) is used in conjunction with expressions of emotion, opinion, or viewpoint. It is also used to describe situations that are considered unlikely or are in doubt, as well as for expressing disagreement, volition, or denial.

There are many common expressions that commonly introduce subjunctive clauses. Examples include:

Es una pena que "It's a shame that"
Quiero que "I want..."
Ojalá que "Hopefully..."
Spanish has two past subjunctive forms. They are almost identical, except that where the "first form" has -ra-, the "second form" has -se-. Both forms are usually interchangeable although the -se- form may be more common in Spain than in other Spanish-speaking areas. The -ra- forms may also be used as an alternative to the conditional in certain structures.

Spanish used to have a future subjunctive tense, but it is now all but extinct. It is never heard in everyday speech, and is usually reserved for literature, archaic phrases and expressions, and legal documents. Phrases expressing the subjunctive in a future time-frame instead employ the present subjunctive. For example: "I hope it will rain tomorrow" would simply be "Espero que llueva mañana" (where llueva is the third-person singular present subjunctive of llover, "to rain").
Presente
Para formar el presente de subjuntivo con verbos regulares, se toma la primera persona del singular del presente de indicativo, se abstrae el radical (p.e. trabajar, el radical es trabaj-) y se añaden las siguientes terminaciones

Verbos terminados en ar Verbos terminado en er o ir
yo -e
tú -es
él -e
nosotros -emos
ustedes/vosotros -en/-éis
ellos -en yo -a
tú -as
él -a
nosotros -amos
ustedes/vosotros -an/-áis
ellos -an

De esta forma tenemos: que yo trabaje, que tu trabajes, que él trabaje, que nosotros trabajemos, que vosotros trabajéis, que ellos trabajen


Pretérito imperfecto y pluscuamperfecto
En el caso del pretérito imperfecto, se añaden las siguientes terminaciones

Verbos terminados en ar Verbos terminado en er o ir
yo -ara
tú -aras
él -ara
nosotros -áramos
ustedes/vosotros -aran/-arais
ellos -aran yo -iera
tú -ieras
él -iera
nosotros -iéramos
ustedes/vosotros -ieran/-ierais
ellos -ieran

Así, con el verbo comer: que yo comiera, que tú comieras, que él comiera, que nosotros comiéramos, que vosotros comierais, que ellos comieran

Answer 2

Another word for "subjunctive" might be "conditional." It is commonly used in Spanish in cases of uncertainty. If you use "if" or "I wish," it is appropriate.

For example, "I have" is "Yo tengo." "I had" is "Yo tuve." But the subjunctive would be used if you wanted to say "If I had," "Si yo tuviera."

This exists in English, as well, but is infrequently used. You would say "I was there," but you would also say "If I were there." This is the subjunctive as used in English.

If anybody thinks I'm wrong, please correct me. I believe I'm right, but my Spanish is a little rusty.