1. El presente del subjuntivo con las cláusulas nominales
Present subjunctive with noun clauses

2. What is this?
This is fancy grammar talk for a sentence with at least 2 clauses; the verb in the first (or main) clause determines whether or not the verb in the second (or dependent, subordinate etc.) clause is subjunctive.
If the verb in the first clause fits into any of several categories such as doubt, emotion, will/wish/want/desire, judgment/opinion, negation and several more (just deal with it), then the verb in the second clause is subjunctive.
Ejemplo:
I want you to learn.
Quiero que aprendas.
The second clause is called the noun clause because it functions like a noun; it is the object of the first verb (what you hope, wish, doubt etc.)

3. If the verb in the second clause has the same subject (yo, tú, ellos, Juan) as the verb in the first clause, you don’t use que and you don’t conjugate the second verb.
Ejemplo:
Juan wants to learn
Juan quiere aprender.

4. When do you use this?
Again, whenever you want to say that someone or something wants or wishes or hopes or doubts or doesn’t believe or doesn’t think or it’s not possible or it is possible or etc. that someone or something else does or is something.

5. Or, look at it this way, with the help of 3 cutesy acronyms:
If the verb in the main clause falls into one these categories the second verb is subjunctive:
Necessity Judgment Wishes
Uncertainty Emotion Emotion
Desire Desire Desire
Emotion Influence Doubt
Impersonal expressions (“es necesario que…”)
Negation
God grant (“ojalá…”)

6. Examples “Ojalá vengas a la fiesta.” “Quiero que Marcos me llame.”
“Yo dudo que salgas tan temprano.”
“Es posible que no me gusten.”

7. What does a subjunctive verb mean in English?
Aprendes = You learn
Aprendas = You learn
Say what? Then how is it different?
Answer: it just feels different to a native speaker.

8. How do you conjugate the subjunctive?
Put the verb in the yo form of the present
Take off the –o
Add these endings:
-ar er / -ir
e emos a amos
es as
e en a an

9. Stem-changing (boot verbs)
Boot verbs in the present are also boot verbs in the present subjunctive
poder
pueda
podamos
puedas
puedan

10. UNLESS
It’s an –ir boot verb; in this case the nosotros form gets the same change as the él and ellos (3rd person) forms in the preterit:
dormir
duerma
durmamos
duermas
duerman

11. -CAR / -GAR / -ZAR
These verbs get the same spelling change as with the preterit, but no accent
tocar → toque etc.
pagar → pague etc.
empezar → empiece etc.

12. Irregulars Dar → dé, des, dé, demos, den
Ir → vaya, vayas, vaya, vayamos, vayan
Ser → sea, seas, sea, seamos, sean
Haber → haya, hayas, haya, hayamos, hayan
Estar → esté, estés, esté, estemos, estén
Saber → sepa, sepas, sepa, sepamos, sepan

13. Conjugate these verbs in the present subjunctive, now, you!
poner
hacer
jugar
roncar
destruir
decir

14. Subjunctive in English
The subjunctive still lives in English, although it’s hanging on for dear life, and we may just put it out of its misery soon enough.
It uses the infinitive form of the verb for the 3rd person singular subject (he, she, it) after clauses with similar meanings to the ones in Spanish that introduce the subjunctive:
It’s necessary that he learn the lesson.
It’s important that Juan be here on time.
Sound weird? That’s because we are in the process of murdering the subjunctive in English.
You still have to learn it in Spanish, though.

15. And if you’re the type of person that needs and can use this, here:
THESE WORDS ALWAYS INTRODUCE THE SUBJUNCTIVE
aconsejar que -to advise that
alegrarse de que -to be happy that
dejar que -to let/allow that
desear que -to wish that
dudar que -to doubt that
(me) emociona que -(I’m) excited that
(me) encanta que – (I) love that
(me) enfada que - (I’m) angry that
(me) enoja que – (I’m) angry that
esperar que - to hope that
estar orgulloso de que – to be proud that
exigir que -to demand that
(me) extraña que – It seems strange that
(me) gusta que – (I) like that

16. Más impedir (i) que -to impede insistir en que -to insist on
(me) irrita que – (I’m) irritated that
lamentar que - to lament that
mandar que -to order that
(me) molesta que – (I’m) bothered that
necesitar que -to need
negar que to deny that
ojalá que hopefully
oponerse a que -to oppose
pedir (i) que -to ask that
permitir que -to permit that
preferir (ie) que -to prefer that
prohibir que - to prohibit
querer (ie) que -to want
recomendar (ie) que to recommend that
rogar (ue) que -to beg that
sentir (ie) que – to regret that
(me) sorprende que – (I’m) surprised that
sugerir (ie) que -to suggest that
suplicar que -to beg that
temer que – to fear that
tener miedo de que – to be scared that

17. Y más THESE IMPERSONAL EXPRESSIONS ALWAYS INTRODUCE THE SUBJUNCITVE
es absurdo que it’s absurd that
es agradable que - it’s agreeable that
es bueno que - it’s good that
es dudoso que - it’s doubtful that
es escandaloso que - it’s scandalous that
es importante que - it’s important that
es imposible que - it’s impossible that
es improbable que - it’s improbable that
es indispensable que - it’s indispensable that
es inútil que - it’s useless that
es justo que - it’s right / just that
es malo que - it’s bad that
es mejor que - it’s better that
es necesario que - it’s necessary that
es peor que - it’s worse that
es posible que - it’s possible that
es probable que - it’s probable that
es raro que - it’s rare that
es ridículo que - it’s ridiculous that
es sorprendente que - it’s surprising that
es triste que - it’s sad that
es una lástima que - it’s a shame that
es útil que - it’s useful that
más vale que - it’s better that
no es que - it’s not that
no es cierto que - it’s not certain that
no es evidente que - it’s not evident that
no es obvio que - it’s not obvious that
no es verdad que - it’s not true that
ojalá que - hopefully

18. Not subjunctive THESE WORDS ALWAYS INTRODUCE THE INDICATIVE
aprender que -to learn that
comprender que -to understand that
creer que -to believe that
darse cuenta de que -to realize that
entender que -to understand that
estar cierto que -to be certain that
estar seguro que -to be sure that
oír que -to hear that
opinar que -to think (opine) that
parecer que -to seem that
pensar que - to think that
saber que -to know that
ver que -to see that