1. El Subjuntivo
There are two moods in Spanish: the indicative and the subjuntive
You have been using the indicative mood to state things that are real and factual in the present tense, the preterite and the imperfect.
The subjuntive allows you to express doubt, hopes and wishes (among other things that are not concrete).

2. How do you form the subjuntive?
Do you remember how to make formal commands?
For –ar verbs go to the “yo” form of the verb, drop the “o” and attach –e or –en.
For –er and –ir verbs you go to the “yo” form of the verb, drop the “o” and attach –a or –an.

3. El subjuntivo
For the subjunctive you attach opposite endings to every form.
The first person and third person singular are the same.

4. Subjunctive of -ar verbs like “comprar”
The endings for “ar” verbs in the subjunctive are:
Comprar:
e, es, e, emos, éis, en
compre, compres, compre, compremos, compréis, compren
Now you put the verb bailar into the subjunctive:
baile, bailes, baile, bailemos, bailéis, bailen

5. Subjunctive of “er” and “ir” verbs
The subjunctive endings for “er” and “ir” verbs are: a, as, a, amos, áis, an
Put hacer into the subjunctive:
haga, hagas, haga, hagamos, hagáis, hagan
Put decir into the subjunctive:
diga, digas, diga, digamos, digáis, digan
Put poder into the subjunctive:
pueda, puedas, pueda, podamos, podáis, puedan
Notice that the stem-changing rules are the same as in the indicative.

6. Irregular verbs
Some verbs have irregular forms because they have irregular yo forms. The verbs ir, ser, dar have forms that need to be memorized. Remember the command forms: 
ve/ no vayas
sé/ no seas
da/ no des

7. Irregular verbs ir vaya, vayas, vaya, vayamos, vayáis, vayan ser
sea, seas, sea, seamos, seáis, sean
dar
dé, des, dé, demos, deis, den

8. Repaso: Subjunctive for hopes and wishes
Preview
Subjunctive for hopes and wishes

9. Subjunctive for hopes and wishes
You already know that the subjunctive mood is used to express hopes and wishes with esperar que, querer que, and preferir que, and to give advice and opinions with es mejor que, es buena idea que, es importante que, aconsejar que, recomendar que, and sugerir que.

10. Subjunctive for hopes and wishes
In Spanish the subjunctive usually appears in the dependent or subordinate clause, and is introduced by the conjunction que after the main clause.
Espero que el viaje a Toledo sea divertido.
I hope the trip to Toledo is fun.
Te recomiendo que des una caminata por la ciudad.
I recommend you take a walk around the city.
Main clause
Subordinate clause
Main clause
Subordinate clause

11. Subjunctive for hopes and wishes
The subjunctive is used when the subjects of the main clause and the subordinate clause are different.
Espero que Carmen pueda acompañarnos a Guadalajara.
I hope Carmen can come with us to Guadalajara.
Óscar sugiere que nosotros llevemos un picnic al lago.
Oscar suggests we bring a picnic to the lake.
different subjects
different subjects

12. Subjunctive for hopes and wishes
When there is no change of subject, an infinitive follows the verb in the main clause.
Gloria prefiere ir al bosque.