Present Subjunctive

The subjunctive isn't really considered to be a tense but rather a mood. It reflects how the speaker feels about an action.

The subjunctive mood is used to express doubt, uncertainty, subjectivity, desire.

Clauses that Indicate Use of the Subjunctive

Present Subjunctive

Start with the yo form of the present indicative.
Then drop the -o ending.
Add the following endings:

Verbs with irregular first persons in present indicative:

The changes in the first person carry over to their subjunctive form.

Conocer – conozca, conozcas, conozca, conozcamos, conozcáis, conozcan
Tener – tenga, tengas, tenga, tengamos, tengáis, tengan
Salir – salga, salgas, salga, salgamos, salgáis, salgan

Stem-changing -ar and -er verbs:

These are conjugated like regular subjunctives (using 'yo' form of indicative) except the stem-change doesn't occur in the nosotros/vosotros forms:

pensar, piense, pienses, piense, pensemos, penséis, piensen

Stem-changing -ir verbs:

These are conjugated like regular subjunctives (using “yo” form of the indicative) except the stem change in the nosotros and vosotros forms follows these patterns:

o:ue verbs change o to u
e:ie verbs change e to i
e:i verbs change e to i

dormir – durmamos
sentir – sintamos
pedir – pidamos

Orthographic Changes to Present Subjunctive Verbs:

Some verbs require changes to their spelling in order to keep their pronunciation.

-zar
- z changes to c before e
- empezar - empiece

-ger or -gir
- g changes to j before a
- coger - coja

-guir
- gu changes to g before a
- seguir - siga

-car
- c changes to qu before e
- buscar - busque

-gar
- g changes to gu before e
- pagar - pague

-uir
- add y before a
- huir - huya

Irregular Verbs in Present Subjunctive

There are only six main irregular verbs in the present subjunctive:

Dar - to give
Estar - to be
Haber - to have (auxiliary verb)
Ir - to go
Saber - to know
Ser - to be

Clause	Translation
a menos que …	unless ...
antes (de) que …	before ...
después (de) que …	after ...
dudar que …	to doubt that ...
en cuanto …	as soon as ...
es dudoso que …	it's doubtful that ...
es fácil que …	it's likely that ...
es importante que …	it's important that ...
es imposible que …	it's impossible that ...
es improbable que …	it's unlikely that ...
es incierto que …	it's uncertain that ...
es (una) lástima que …	it's a pity that ...
es necesario que …	it's necessary that ...
esperar que …	to wish that ...
es posible que …	it's possible that ...
es preciso que …	it's necessary that ...
es preferible que …	it's preferable that ...
es probable que …	it's probable that ...
hasta que …	until ...
insistir en que …	to insist that ...
mientras que …	while ...
negar que …	to deny that ...
no creer que …	not to believe that ...
no es cierto que …	it's not certain that ...
no estar seguro de que …	to not be sure that ...
no es verdad que …	it's not true that ...
no imaginarse que …	to not imagine that ...
no parecer que …	to not seem that ...
no pensar que …	to not think that ...
no suponer que …	to not suppose that ...
ojalá …	perhaps ...
para que …	in order that ...
pedir que …	to ask that ...
preferir que …	to prefer that ...
prohibir que …	to prohibit that ...
puede ser que …	it may be that ...
querer que …	to want that ...
recomendar que …	to recommend that ...
sin que …	without ...
sugerir que …	to suggest that ...
temer que …	to fear that ...
tener miedo de que …	to be afraid that ...

Verbs ending in -AR	Verbs ending in -ER and -IR
-en	-an
-éis	-áis
-emos	-amos
-e	-a
-es	-as
-o	-o

Dar	Estar	Haber	Ir	Saber	Ser
des	estés	hayas	vayas	sepas	seas
dé	esté	haya	vaya	sepa	sea
demos	estemos	hayamos	vayamos	sepamos	seamos
deis	estéis	hayáis	vayáis	sepáis	seáis
den	estén	hayan	vayan	sepan	sean
dé	esté	haya	vaya	sepa	sea