Condicionales con si
Two sentences cover almost every si you will ever need. Si tengo tiempo, te ayudo is a bet on the real world: the condition might happen, and if it does, so does the rest. Si tuviera tiempo, te ayudaría is a daydream: it is not happening, and both of you know it. English marks the difference with a tense — 'if I have' against 'if I had' — and Spanish does the same thing, with tighter rules about which tense goes where. One of those tenses is new today, the imperfecto de subjuntivo, and you can build every form of it out of the pretérito you already own. One rule never bends: after si, never the futuro and never the condicional.
The little word, and where the comma goes
si carries no accent. sí with one is 'yes', and the two are not related — Sí, si quieres. is a perfectly normal answer meaning 'Yes, if you want to.' The si half of the sentence can come first or second, and that is purely a matter of what you want to emphasise. When it leads, a comma separates the halves: Si llueve, me quedo en la casa. When it follows, no comma: Me quedo en la casa si llueve. Both are the same sentence. What never changes is which tense lives on which side — the si clause and the main clause have separate jobs, and today is about not letting them swap.
Type 1: the real condition
The shape is si + present indicative, then the main clause in whatever fits: present, futuro, ir a + infinitive, or a command. Si tengo tiempo, paso por tu casa. Si mañana no llueve, vamos a la playa. Si estudias, vas a salir bien en el examen. Si no comes, te vas a enfermar. Si quieres, ven con nosotros. Use this one whenever the condition is genuinely on the table: it might rain, you might have time, the money might show up. Notice what the verb after si is doing in the second example — the sentence is about tomorrow, but the verb is present. That is the rule that costs learners the most: Spanish will not let the futuro stand behind si, however future the meaning is. Si mañana lloverá is not a sentence anyone says. Put the future in the other half, where it belongs, and leave si with a plain present.
Building the imperfecto de subjuntivo
For the unreal half you need a form you have not met, and it is built entirely out of a tense you already know. Step one: take the ellos row of the pretérito — hablaron, comieron, vivieron, tuvieron, fueron. Step two: drop the -ron, leaving habla-, comie-, vivie-, tuvie-, fue-. Step three: add -ra, -ras, -ra, -ramos, -ran. That gives you five rows, the way every ladder in this course runs: yo tuviera, tú tuvieras, él tuviera, nosotros tuviéramos, ustedes tuvieran — and ustedes tuvieran covers ellos too, friends and strangers alike. The only written accent in the set sits on the nosotros row: habláramos, comiéramos, tuviéramos, fuéramos. The reward for this recipe is that every irregular verb comes free, because the irregularity is already sitting in the pretérito: hicieron → hiciera, dijeron → dijera, pudieron → pudiera, supieron → supiera, estuvieron → estuviera, quisieron → quisiera, vinieron → viniera, and fueron → fuera for both ser and ir. If you can say it in the pretérito, you can say it here.
One note on -ra and -se
You will run into a second set of endings in older books, in song lyrics and in text printed in Spain: hablase, tuviese, fuese, pudiese. It means exactly the same thing as hablara, tuviera, fuera, pudiera — there is no difference in sense, only in flavour. Across Latin America the -ra forms are the everyday choice in speech and in writing, and they are what this course teaches. Learn to recognise the -se set when you read it, and let your own mouth produce -ra.
Type 2: the unreal present
The shape is si + imperfecto de subjuntivo, then the main clause in the condicional you built last lesson. Si tuviera un millón de pesos, compraría una casa cerca del mar. Si viviéramos en Lima, comeríamos ceviche todos los domingos. Si hablara tres idiomas, trabajaría en otro país. Every one of those describes something that is not the case: I do not have the million, we do not live in Lima. The two tenses are locked to their sides — the subjunctive lives with si, the condicional lives in the other half — and they never trade places. Turn the sentence around and nothing changes except the comma: Compraría una casa cerca del mar si tuviera un millón de pesos. This is the pattern behind most of what sounds sophisticated at B1, and it is worth drilling until it comes out whole.
What the choice tells your listener
The grammar is doing more than bookkeeping — the tense you pick is a claim about the world. Si tengo plata, voy contigo says the trip is genuinely possible; I may well have the money. Si tuviera plata, iría contigo says the opposite: I do not have it, so I am not going, and this is regret rather than a plan. Same two people, same trip, completely different message. Type 2 also does polite work that Type 1 cannot. Si pudiera, le ayudaría softens a refusal into something kind; Si fuera usted, hablaría con el profe primero offers advice without ordering anybody around. When you want to sound careful rather than blunt, reach for the unreal one on purpose.
Never after si — with one exception
Two forms are barred from the si clause: the futuro and the condicional. Si tendré tiempo and Si tendría tiempo are both wrong, and the second one is especially tempting because English says 'if I would'. After si you have exactly two choices: the present (Type 1) or the imperfecto de subjuntivo (Type 2). Now the exception, which is not really an exception at all. Spanish uses the same word si for 'whether', and that si introduces a hidden question, not a condition: No sé si vendrá mañana. Me preguntó si iría a la fiesta. There the futuro and the condicional are perfectly correct, because nothing is being conditioned — you are reporting a question. Test it in English: if 'whether' fits, the ban does not apply.
Templates worth memorising whole
Five patterns will carry you through most conversations. Si fuera tú, no diría nada — 'if I were you', the single most useful unreal sentence in the language, and note that Spanish says fuera tú with the subject pronoun, not fuera ti. Si yo estuviera en tu lugar… is its slightly softer cousin. ¿Qué harías si…? opens every daydream ever started at a kitchen table. Si pudiera, … and Si supiera, … are ready-made openings for apologies and confessions. Two smaller pieces travel with the same grammar. como si always takes the imperfecto de subjuntivo, no matter what tense the rest of the sentence is in: Habla como si fuera de Bogotá. And por si means 'in case' and stays in the plain present: Llevo el suéter por si hace frío. Por si acaso on its own is 'just in case', and you will hear it constantly.
Money, dreams and free time
el dinero is the neutral word and works everywhere, but in most of South America the everyday one is la plata — No tengo plata — while Mexico says la lana. un millón always takes de before a noun: un millón de pesos, dos millones de personas. el país keeps its accent on the i, and the plural is los países. el idioma is masculine in spite of the -a, like el problema and el mapa; la lengua is the same idea seen from the other side, and also the thing in your mouth. Watch libre closely: it means free as in unoccupied or unconstrained — un sábado libre, el baño está libre — while free of charge is gratis. El café fue gratis and El café estaba libre are two very different afternoons. la esquina is the outside corner where two streets meet, which is where half the region waits for the bus; the inside corner of a room is el rincón. soñar changes its stem like poder: sueño, sueñas, sueña, soñamos, sueñan, and you dream con something: Soñé con mi abuela. And quedarse is to stay put — Me quedé en la casa, Quédate un ratito — where the plain quedar means to be left over: Me queda un peso.
