1. Subjuntivo
Presente

2. RED can help you remember!
The Present subjunctive is mood that expresses:
Requests, wishes, needs, and desires
Emotions and subjective feelings
Doubt and uncertainty

3. Main Clause. Que. Dependent clause (Present indicative)
Main Clause Que Dependent clause (Present indicative) (Present subjuntive)
Not only does the subjunctive express these moods, but it appears within a particular sentence structure. It is the meaning of the verb or verb phrase in the main clause that triggers the use of the subjunctive in the dependent clause.
Yo quiero que vengas al partido.
Me alegro de que estés en la clase.
Yo dudo que ganen Los Lakers.

4. Different subjects in main and dependent clause.
The subject of both sentences are usually different and refer to different people; otherwise an infinitive is used.
Queremos que tú toques el piano.
but
Queremos tocar el piano.

5. Ojalá (I / Let’s hope) + que
The exclamation ojalá + que is always used with the subjunctive. Its origin is Arabic and it means God (Allah) willing. The use of que is optional.
Ojalá que la clase comprenda el subjuntivo.

6. Verbos como Gustar
The following verbs that are conjugated like gustar are used in the third person singular indicative when followed by que and a subordinate clause in the subjunctive.
Me encanta que estudies español.
Me fascina que escuches música latina.
Ejemplos: Encantar, enojar, fascinar, gustar, fastidiar, irritar, molestar, preocupar, sorprender, frustar.

7. Verbs and impersonal expressions of doubt and uncertainty.
Verbs and impersonal expressions of doubt and uncertainty such as dudar, es imposible, no creer, trigger the subjuntice when they appear in the main clause of the sentence structure below.
Es imposible que yo pueda ir a la fiesta, hay mucha tarea.
Es necesario que tú estudies las reglas gramaticales.

8. Verbal expressions of certainty = present indicative.
Verbal expressions of certainty in the main clause usually require the indicative in the dependent clause.
Es verdad que tenemos un examen mañana.
No dudo que el professor habla bien el español.

9. Creer and Pensar
Creer and pensar are used in the negative or to ask a question, the subjuntice is often used. It implies that the speaker is unsure of what the answer will be.
¿Crees que llueva (llover) mañana?
No creo que el profesor cambie el examen.
No pienso que mi novia vaya a la fiesta. Vs
Pienso que mi novia va a la fiesta también.

10. Quizás and Tal vez
When quizás and tal vez are used to express doubt, the subjunctive is generally used. The word que is omitted.
Quizás vaya al concierto contigo.
Tal vez saque un A en este examen.