What is the subjunctive mood used for??
I know the endings change but I never know when to use it...grrr
3 Answers
Hola Mamisita, y bienvenida al foro!
Marianne has provided you with a great link, but let me try to give you a little background.
First of all, the subjunctive mood is usually not used by itself; in other words, there needs to be a main clause that "sets the tone", and then, provided that certain criteria are present in the main clause, the subjunctive would be used in the dependent clause.
Generally speaking, you need two clauses and a change of subject before you can even start thinking about using the subjunctive. Here are guidelines:
IF the main clause indicates doubt, denial disbelief or non-existence, the dependent clause will be in the subjunctive (provided there is a change of subject). "Dudo que vaya" - I doubt that he is going. "No existe persona que hable cien lenguas" - There is no person who speaks 100 languages. "No creemos que lo hayan visto" - We don't believe that they have seen it.
IF the main clause indicates any sort of order, suggestion, advice, or warning, the dependent clause will be in the subjunctive: "Exigen que estudie" - They demand that I study. "Aconsejamos que lo hagas de inmediato" - We advise you to do it immediately.
IF the main clause is followed by a non-habitual event that has not yet occurred, the dependent clause is in the subjunctive: "Te veo cuando vengas." - I will see you when you get here. "Dimelo tan pronto como sepas" - Tell me as soon as you know.
This is a total nutshell, and there are many more uses. However, however, generally speaking, the subjunctive is used in dependent clauses that refer to events that have not yet occurred, do not exist, or are a result of conditions expressed in the main clause.
Be sure to check out the link.
I hope this has helped!
I would have said that subjunctive is used to confuse gabachos like me but, as usual, Marianne-'s answer was faster and far more helpful than mine. Welcome to the forum!
Hi Mamisita. Welcome to the forum. 
Unfortunately, I can't give you a simple answer to your question. You have to study the subjunctive and its uses to understand it.
The lessons here are great for a start on how/when to use the subjunctive, and here's a good article on learning when to use the subjunctive mood.
