Declaring things and the subjunctive
I'm still a little 
unclear on what is a declaration and what is not in deciding whether to use the subjunctive. Say my friend Juan is coming over and I am going to pay him when he gets here.
If Juan comes, I will pay him.
Si Juan viene, lo pago.
Even though Juan hasn't arrived, I think there is a high probability that he will come, so I use the indicative.
When Juan comes, I will pay him.
Cuando Juan venga, lo pago.
I have read that the subjunctive always has to be used after cuando, because I can't declare that Juan has come because it is in the future, even if I have the same degree of certainty that led me to use the indicative in the first sentence. In fact, in English the second sentence implies a stronger belief that Juan will actually come.
So my question is, can I say in this case
Cuando Juan viene, lo pago.
9 Answers
¿Qué me darías si hilo toda esta paja en oro?
Hmm... the correct way to say this would be "¿Qué me darías si hilara toda esta paja en oro?" This type of "si-clause" requires the imperfect subjunctive due to the use of the conditional. The same construction in English actually uses the subjunctive as well, it's just not as easily recognizable:
What would you give me if I were to draw all this straw into gold?
The use of "were to draw" instead of "was to draw" is an indication of the subjunctive. In Spanish, the use of the subjunctive is much clearer, as a completely different conjugation of a verb is used. In English, it's not so obvious, and that probably leads to the misconception that English does not utilize the subjunctive.
In regards to the initial question...
If Juan comes, I will pay him.
Si Juan viene, lo pago.
Even though Juan hasn't arrived, I think there is a high probability that he will come, so I use the indicative.
When Juan comes, I will pay him.
Cuando Juan venga, lo pago.
There are basically three types of si-clauses:
- Si + present, present/future/imperative
- Si + imperfect subjunctive, conditional
- Si + pluperfect subjunctive, conditional perfect/pluperfect subjunctive
Using your example...
- Si Juan viene, lo pagaré (If Juan comes, I will pay him)
- Si no quiero pagar a Juan, no lo hago. (If I don't want to pay Juan, I don't. --> habitual actions that occur when condition is met).
- Si pagas a Juan, no le des mucho dinero. (If you pay Juan, don't give him a lot of money).
- Si (yo) pagara a Juan, tendría que darle mucho dinero. (If I were to pay Juan, I would have to give him a lot of money).
- Si hubieras pagado a Juan, no habrías/hubieras tenido ese problema. (If you had/were to have paid Juan, you wouldn't have had that problem. In this type of sentence, either the conditional perfect or pluperfect subjunctive can be used in the independent clause. I believe it's a regional thing...)
On to the other question...
I have read that the subjunctive always has to be used after cuando...
The indicative is used with "cuando" when referring to present/habitual actions and past actions (because you can declare them). The subjunctive is used with "cuando" whenever you are referring to future/anticipated actions (because you can not declare that those can happen).
- Los estudiantes se sientan cuando la profesora entra. (The students sit down when the teacher enters. --> Habitual, declarable action).
- Los estudiantes se sentaron cuando la profesora entró. (The students sat down when the teacher entered. --> Past, declarable action).
- Los estudiantes van a sentarse/se sentarán cuando la profesora entre. (The students are going to/will sit down when the teacher enters. --> What if the teacher never enters? Anticapted/future event, "undeclarable" action).
Well, I hope this helps. 
Good question.
It depends on whether Juan coming and your paying him is a habitual act, or if you are referring to a specific time.
For example - if you mean to say something like: when Juan comes, I (always) pay him, you will say "Cuando viene Juan (siempre) lo pago." In this case you are merely relating to someone else a habitual pattern in your schedule.
On the other hand, if you are talking about a specific event that has not yet ocurred - even if you are sure that this event will occur - you must use subjunctive. "Cuando venga Juan, lo pago/lo pagaré/lo voy a pagar."
The subjunctive in this case falls into that "shadowy" area of Spanish that language philosophers mull over - the supposed fatalism of dependent clauses in the future.
I'm afraid the rule that asserts you use subjunctive after cuando is precisely just a rule, that is, it doesn't work in every case. You certainly cannot say
Cuando Juan viene, lo pago (the money) / le pago (I pay the money to him)
using indicative, because you don't know "cuándo", or because "cuándo" doesn't matter (whenever). But you certainly can (sometimes, you must) use indicative after "cuando" in some cases. For examples of mandatory indicative, we don't use subjunctive when we say something about the moment "cuando" that applies just to that moment, and no to any possible moment:
- No va a casarse en mayo. Cuando se *case / casa / casará / es en abril. - ¿Vas a ir en agosto? Pues te lo advierto: cuando tú vas / *vayas hace un calor terrible allí.
As to Nick's answer, I find it very useful, though I'd like to make a precision:
The subjunctive is used with "cuando" whenever you are referring to future/anticipated actions (because you can not declare that those can happen).
If we have to believe that no-declaration must be chosen every time "yon cau not declare that those can happen", then the following indicatives for easily declarable facts would be allowed, which is not the case:
- Cuando ***moriré... - Cuando este cigarrillo se apagará... - Cuando terminará la película...
Perhaps a more guiding explanation would be the following: to declare or not a verb related to a moment (cuando, el momento en que, el día que..., mientras...) implies to declare or not the moment itself. To declare a moment would mean experience and identification of that moment by the part of the speaker (hence the normal use of indicative in the past), and not to declare would imply no experience and no identification (hence the normal subjuntive for the future). From this perspective, we can now understand why in Spanish we say
"Cuando muera (porque moriré sin duda")
meaning: 'I declare that "moriré" (as a matter of fact) but I can not (or I don't want to, in the case of a scheduled death) identify the precise moment of "cuando".'
It seems to me somewhat like if you said in English "whenever" every time you wanted to refer to some event in the future...
Nick, great answer!!
You will be officially named "grammar guru" of this site
I found this example in a fairy tale "Rumpelstiltskin", but I´m not sure if this will help (I´m still a long way from such complex grammar issues)
¿Qué me darías si hilo toda esta paja en oro?
What will you give me if I draw all this straw into gold?
Aha!!!! Super!
...you must use the subjunctive in the first part , right after cuando:
cuando venga Juan.....
The second part of the sentence can have all the tenses used by Mountain.
Thank both of you sooo much, Mountain Girl and Heidita...
By the way, I start verbs in my grammar from the company in Barcelona, Difusion: Grámatica básica del estudiante español just as soon as I finish the chapters on pronouns. Maybe I will finally be able to know what all of the forum members are talking about when they refer to the subjunctive.
(Well, it just occurred to me that my first encounter with the name Heidi was a little mountain girl my Mother read to me about -- (Swiss mountains, though, Mountain Girl, Heidi
What if the sentence involved someone other than yourself, say:
When Juan comes, Julio will pay him.
Would you still be able to declare the second part? If so, would you have to put it in the future tense to give it a sense of probability?
HI Janice, you must use the subjunctive in the first part , right after cuando:
cuando venga Juan.....
The second part of the sentence can have all the tenses used by Mountain.
As I was reading your explanation, Mountaingirl, I was thinking how well you were explaining something that I haven´t a clue about yet. But then....
you must use subjunctive. "Cuando venga Juan, lo pago/lo pagaré/lo voy a pagar."
and yet .... the present subjunctive of pagar is "pague"; the future subjunctive, "pagare" (accent on the second syllable, no diacritical mark needed).
What have I misunderstood....?
