quiero que vengas: the mood English almost lost, alive and essential in Spanish
The subjunctive is not a tense but a mood: it marks what is wished, doubted, or felt — rather than stated as fact. English has traces ("I suggest he be on time"); Spanish uses it constantly.
Fact: Sé que vienes. (I know you are coming — indicative.)
Wish: Quiero que vengas. (I want you to come — subjunctive!)
Notice the English: "I want YOU TO COME" — Spanish says "I want THAT you come", with the verb in the subjunctive.
Start from the yo form of the present, drop -o, add the opposite vowel endings: -ar verbs take -e endings, -er/-ir verbs take -a endings.
hablar → hable, hables, hable, hablemos, habléis, hablen
comer → coma, comas, coma, comamos, comáis, coman
vivir → viva, vivas, viva, vivamos, viváis, vivan
Starting from the yo form keeps the irregularities: tengo → tenga, hago → haga, conozco → conozca.
Six verbs don't follow the yo-form trick — memorise them with the classic acronym-friendly list.
ser → sea · estar → esté · ir → vaya
saber → sepa · dar → dé · haber → haya
Espero que sea fácil. (I hope it is easy.) · ¡Que te vaya bien! (Hope it goes well!)
These six appear in every exam. Sea, esté, vaya, sepa, dé, haya — chant them.
The subjunctive appears after a trigger + que + change of subject. The B1 trigger families:
Wish/request: quiero que / espero que / pido que + subj.
Emotion: me alegro de que / siento que / me molesta que + subj.
Impersonal: es importante que / es necesario que / es mejor que + subj.
Same subject → infinitive: Quiero ir. Different subjects → que + subjunctive: Quiero que vayas.
Some triggers are single words. The loveliest is ojalá (from Arabic "law šā' Allāh" — God willing): hope itself, always + subjunctive.
Ojalá llueva café. (I hope it rains coffee — as the song goes.)
Ojalá apruebes el examen. (I hope you pass the exam.)
Que tengas buen viaje. (Have a good trip! — a wish, so subjunctive.)
Good-wish formulas all hide a subjunctive: que aproveche, que te mejores, que cumplas muchos más.
Traps for English speakers
These are the errors English speakers make most often.