My favorite "tense" in Spanish is the subjunctive. The subjunctive is truly more of a mood than it is a tense. According to etymology.com, the definition of subjunctive is a "mood employed to denote an action or state as conceived and not as a fact," English barely uses the subjunctive, so it is difficult for English speakers to grasp.
The subjunctive is fairly easy to conjugate compared with, for example, the preterite. The subjunctive is formed by going to the “yo” in the present tense, dropping the “o” and adding the opposite ending (and nosotros and vosotros don’t stem-change, which learners already know as a rule from the present tense). The six main irregulars are the same as some of the main irregulars in the negative “tú” commands, and some of the same rules from the preterite apply with regards to “car, gar, zar” verbs. The actual conjugation mostly builds on knowledge that the learner already has, so review of already learned tenses gives learners the confidence to accurately conjugate verbs in the subjunctive.
3. Haga (then apply this to all conjugated forms: yo, tú, ud, etc.)
1. Sacar-->Saque (then apply this to all conjugated forms: yo, tú, ud, etc.) There is no accent mark on the car, gar, zar in the subjunctive because the preterite 'yo' forms already have an accent mark to differentiate between the two.
The structure requires two subjects with the word “que” in between linking them. The first subject’s action verb is conjugated in the indicative and the second one is conjugated in the subjunctive. The second subject is influenced by the emotions, wants, or uncertainty of the first subject. Learning the structure, like the conjugation, takes some practice, but it is not the hardest part about mastering the subjunctive.
So what is so tricky then? People think too hard about whether they should use the subjunctive mood versus the indicative. Relax, you already know what the indicative is without knowing that you know it. The indicative is a large umbrella that encompasses every tense that you’ve learned up until the subjunctive. Nothing that you have already learned to say (such as what time it is, the weather, describe someone's personality, or what happened in the past) will change, but rather you learning to describe a new world.
The indicative is like our world and the world before Alice went down the hole; the subjunctive is like when Alice is down there and bizarre events can happen. When we express what we want or do not want, hope, or desire to happen and whether it actually happens depends on another subject, we are using the subjunctive. There is a difference between “It is raining (Llueve)” which describes the world and “I want it to rain (Quiero que llueva)” which expresses YOUR WORLD. That is to say, you are expressing your hope that another subject acts in accordance with your wants. Everything you already know how to say continues to be used to describe reality, and now you will also know how to express the hypothetical.
Small talk about the weather gets old quickly and you can't develop good relationships based on conversations about how many books Juan has. Congratulations, you are now amping up your conversational skills by being able to describe inner worlds rather than being limited to only describing what occurs in real life. ¡Espero que esta lección los ayude a entender el subjuntivo!