Lesson 38: Conditional sentences with si — the three types

Vocabulary: hypothetical situations, cause-effect, regret (~32 words)

How to work with this lesson

  1. Read — get the three types and their formulas (10 minutes)
  2. Say it out loud — take ONE idea and run it through all three types: "if I have time / if I had time / if I had had time"
  3. Speed up — drill the "what would you do if…" matrix until the answers fly out on their own

Knowing the rule = 5%. Training your mouth = 95%. This is a synthesis lesson. It pulls together imperfecto de subjuntivo (L37) and conditional simple (L28). If either of those isn't on autopilot yet, jog back through them before pushing on.


Part 1: The master rule

Condition = "if". Result = "then". Spanish has three fixed schemas for si-sentences. Memorize them as formulas — and you can build any "if…" you want.

The good news for English speakers: Spanish si-sentences map almost one-to-one onto English if-sentences. English uses the SAME three patterns, just with different verb forms:

TypeEnglishSpanish
1. Real / openIf it rains, we stay. / If it rains, we'll stay.si + presente → presente / futuro / imperativo
2. Hypothetical (present/future)If I had money, I would travel.si + imperfecto de subjuntivocondicional simple
3. Counterfactual pastIf I had studied, I would have passed.si + pluscuamperfecto de subjuntivocondicional perfecto

THE ONE RULE YOU MUST INTERNALIZE: after si in a hypothetical, NEVER use the conditional. Not si tendría (✗) — it has to be si tuviera (✓). Same trap as in English: native speakers do say "if I would have known" colloquially, but it's not standard. In Spanish it's flat-out wrong.

Also: never use present subjunctive after si in a conditional. Present subjunctive lives after triggers like cuando, aunque, para que, ojalá — but never directly after si. Si tenga tiempo (✗) is wrong. It's si tengo tiempo (✓, real) or si tuviera tiempo (✓, hypothetical).


Part 2: Type 1 — Real condition (presente → presente / futuro)

When: you're talking about a realistic possibility in the present or future. Something that may well happen.

Formula:

si + PRESENTE  →  PRESENTE / FUTURO / IMPERATIVO
ConditionResultEnglish
Si tengo tiempo,voy al cine.If I have time, I go to the cinema.
Si tengo tiempo,iré al cine.If I have time, I'll go.
Si llueve mañana,no saldremos.If it rains tomorrow, we won't go out.
Si me llamas,te contesto.If you call me, I answer.
Si tienes hambre,come algo.If you're hungry, eat something.

English speaker's trap: in English you can say "if it WILL rain" only in special senses ("if it will help, I'll do it"); the normal future-conditional in English is "if it RAINS, I will…". Spanish is the same — never si lloverá (✗). After si in Type 1: presente, always. The future stays in the main clause: Si llueve, lloverá sobre nosotros también.

Word order: both orders work. Si llueve, no salimos. = No salimos si llueve. When the si-clause comes second, no comma.


Part 3: Type 2 — Hypothetical present (imperfecto de subjuntivo → condicional)

This is the most important type for B2/C1. It's where you talk about wishes, hypotheses, advice, and "if I were you" — things that aren't true right now but you can imagine.

Formula:

si + IMPERFECTO DE SUBJUNTIVO  →  CONDICIONAL SIMPLE

Exact English parallel:

if + PAST SUBJUNCTIVE          →  WOULD + verb
("if I were", "if I had")
ConditionResultEnglish
Si tuviera tiempo,iría al cine.If I had time, I'd go to the cinema.
Si tuviera dinero,viajaría por el mundo.If I had money, I'd travel the world.
Si fuera tú,no lo haría.If I were you, I wouldn't do it.
Si supiera la respuesta,te la diría.If I knew the answer, I'd tell you.
Si pudiera,dejaría el trabajo.If I could, I'd quit my job.

Notice how clean the mapping is. "If I were you" = Si fuera tú. "If I had money" = Si tuviera dinero. "I would travel" = viajaría. The Spanish "would" lives inside one word (the -ía ending of the conditional); the English "would" is a separate auxiliary. Otherwise, same grammar.

Imperfecto de subjuntivo refresher (from L37)

Verb-ra formVerb-ra form
tenertuvierahacerhiciera
ser / irfueraestarestuviera
sabersupieradardiera
poderpudieravenirviniera
haberhubieradecirdijera
vervieraquererquisiera

Tip: -ra and -se forms (tuviera / tuviese) are interchangeable, but -ra is far more common in everyday speech. In conditionals, go with -ra without hesitation.

Conditional simple refresher (from L28)

Endings: -ía, -ías, -ía, -íamos, -íais, -ían — the same as imperfect -er/-ir. They attach to the infinitive (hablar → hablaría, comer → comería, vivir → viviría) or to the irregular future stem: tendr-, har-, dir-, podr-, sabr-, querr-, saldr-, vendr-, habr-, pondr-, vendr-. So: yo tendría, tú harías, él diría, nosotros podríamos, vosotros sabríais, ellos querrían.


Part 4: Type 3 — Counterfactual past (preview; full coverage in L39)

When: you're talking about something that didn't happen in the past, imagining an alternative. "If I had studied, I would have passed." Pure regret or speculation about a closed chapter.

Formula:

si + PLUSCUAMPERFECTO DE SUBJUNTIVO  →  CONDICIONAL PERFECTO
ConditionResultEnglish
Si hubiera estudiado,habría aprobado.If I had studied, I would have passed.
Si lo hubiera sabido,te habría llamado.If I had known, I would have called you.
Si hubiéramos salido antes,no habríamos llegado tarde.If we'd left earlier, we wouldn't have been late.

Composition: hubiera + participle in the condition, habría + participle in the result. Exact map onto English "had + past participle" / "would have + past participle".

For now, just recognize the pattern. Lesson 39 covers pluscuamperfecto de subjuntivo in full: the hubiera/hubieras/... conjugations, mixed types (Si hubiera estudiado, ahora tendría un buen trabajo — past condition, present result), and the fine print.

Today's job: spot the pattern in speech and texts. You don't have to build them yet — but when you see Si hubiera… habría…, you know that's "if I had…, I would have…".


Part 7: "If I were you…" and giving advice

Si yo fuera tú… is the standard tactful way to give advice — exactly like English "If I were you…".

SpanishEnglish
Si yo fuera tú, no lo haría.If I were you, I wouldn't do it.
Si fuera tú, hablaría con él.If I were you, I'd talk to him.
Yo que tú, lo intentaría.If I were you, I'd try it. (very colloquial)
En tu lugar, esperaría un poco.In your place, I'd wait a bit.

Note: Yo que tú… is a short, super-common colloquial variant — no si, same meaning. And note: English uses were here ("if I were you"), not "was" — Spanish doesn't have to make that swap because fuera is already subjunctive.


Part 8: Cause-and-effect connectors

A condition is a cause. Results often pick up connectors: "then", "in that case", "otherwise". Below is the glue kit that turns a bare conditional into a fuller thought.

ConnectorEnglishExample
entoncesthen, in that caseSi tienes tiempo, entonces ven.
en ese casoin that caseNo tengo dinero. En ese caso, no compro nada.
de otra manera / de lo contrariootherwiseLlega a tiempo, de lo contrario perderemos el tren.
asíthat waySi lo haces así, funcionará.
por esothat's why, soNo tenía tiempo, por eso no fui.
comosince (at start)Como no tenía tiempo, no fui.

Part 9: Regrets and wishes — ojalá, quisiera

From L37 you know ojalá and quisiera. In a conditional context they work as compressed "if only…" sentences.

SpanishEnglish
Ojalá tuviera más tiempo.I wish I had more time. / If only I had more time.
Ojalá pudiera ayudarte.I wish I could help you.
Quisiera viajar más.I'd love to travel more.
Me gustaría vivir cerca del mar.I'd like to live near the sea.
Qué pena que no estés aquí.What a pity you're not here.

Subtle point: Ojalá + imperfecto de subjuntivo = "I wish…" / "if only…" (not the case right now). Ojalá + presente de subjuntivo = "I hope…" (still possible). Compare: Ojalá venga (I hope he comes) vs. Ojalá viniera (I wish he'd come).


Next up: Lesson 39 — Perfect subjunctive: haya hablado (present perfect subj.) and hubiera hablado (pluperfect subj.). This is the keystone that closes the si-system: you'll get Type 3 in full, plus mixed conditionals (Si hubiera estudiado, ahora tendría un buen trabajo — past condition leading to present result). After that, every "if…then…" thought in Spanish is yours.

Lesson 38: Conditional sentences with si — the three types · Español · Glottos Matrix