Conditional Sentences (Si Clauses) & Sequence of Tenses

Every conditional sentence makes the same basic move — a condition (the si-clause) paired with a consequence (the main clause) — but English lets its “if” clauses flex loosely across tenses in a way Spanish never does. Spanish locks each type of condition to one, and only one, correct pair of tenses: get the pairing wrong, and the sentence stops sounding like a minor stylistic slip and starts sounding simply broken. This chapter doesn’t teach a single new verb form — every tense involved already has its own home (Chapter 34’s simple conditional, Chapter 35’s compound conditional, Chapter 39’s imperfect subjunctive, Chapter 40’s pluperfect subjunctive). What this chapter teaches is the pattern-matching itself: given a condition, which exact pair of tenses does Spanish demand, and why.

Core Pattern: Real/Possible Conditions

Si + present indicative, + present indicative / future / command

A2

When a condition is genuinely open — plausible, still up for grabs, not contrary to any known fact — both clauses stay in the indicative. The si-clause takes the present indicative; the main clause takes the present indicative, the future, or an imperative.

“

Si llueve, no salgo.

If it rains, I'm not going out.

“

Si estudias, aprobarás el examen.

If you study, you'll pass the exam.

“

Si tienes tiempo, llámame.

If you have time, call me.

Building Out: Hypothetical Present Conditions

Si + imperfect subjunctive, + simple conditional

B1

When a condition is contrary to fact right now, or simply unlikely, the pattern shifts entirely: the si-clause takes the imperfect subjunctive (Chapter 39), and the main clause answers with the simple conditional (Chapter 34).

“

Si tuviera dinero, viajaría más.

If I had money, I would travel more.

“

Si fuera tú, no lo haría.

If I were you, I wouldn't do it.

Nuance, Exceptions & Contrast

Hypothetical past conditions: si + pluperfect subjunctive, + compound conditional

B2

When the condition itself is about the past — something that didn’t happen — and its consequence is also about the past, both clauses step one full tense further back: the si-clause takes the pluperfect subjunctive (Chapter 40), and the main clause takes the compound conditional (Chapter 35).

“

Si hubiera estudiado más, habría aprobado el examen.

If I had studied more, I would have passed the exam.

Mixed-time conditions: a past condition, a present consequence

C1

Sometimes a condition about the past has a consequence that’s still being felt right now, in the present — not back then. When that happens, the si-clause still takes the pluperfect subjunctive, but the main clause drops back down to the simple conditional, not the compound one, because the result being described is a present state, not a past event.

“

Si hubiera estudiado, ahora tendría un buen trabajo.

If I had studied, I would now have a good job.

Word order: the si-clause can come first or second

A2

Either clause can lead — Spanish doesn’t require the si-clause to come first the way it usually appears in textbook examples. The meaning doesn’t change either way. When the si-clause comes first, a comma separates the two clauses; when it comes second, no comma is needed.

Si llueve,connectorno salgo.verb

No salgoverbsi llueve.connector

“

No salgo si llueve.

I'm not going out if it rains.

This flexibility holds across every conditional type in this chapter, not just the real/possible one above.

Synthesis: The Complete Reference Table

All four types, side by side

B2

This table is the payoff of the whole chapter — everything above collapses into one lookup:

Type	Si-Clause Tense	Main-Clause Tense	Example
Real / possible	Present indicative	Present indicative, future, or command	Si llueve, no salgo.
Hypothetical present	Imperfect subjunctive (Ch. 39)	Simple conditional (Ch. 34)	Si tuviera dinero, viajaría más.
Hypothetical past	Pluperfect subjunctive (Ch. 40)	Compound conditional (Ch. 35)	Si hubiera estudiado más, habría aprobado el examen.
Mixed-time (past condition, present result)	Pluperfect subjunctive (Ch. 40)	Simple conditional (Ch. 34)	Si hubiera estudiado, ahora tendría un buen trabajo.

A worked passage: four types in context

B2

(1) Si llueve mañana, cancelaremos la excursión. (2) Aunque, la verdad, si yo fuera el organizador, elegiría una fecha con mejor pronóstico. (3) Si hubiéramos revisado el tiempo antes de reservar, habríamos elegido otro fin de semana. (4) Y ahora, si hubiéramos planeado mejor, no tendríamos este problema en absoluto.

(1) If it rains tomorrow, we’ll cancel the trip. (2) Although, honestly, if I were the organizer, I’d choose a date with a better forecast. (3) If we had checked the weather before booking, we would have chosen a different weekend. (4) And now, if we had planned better, we wouldn’t have this problem at all.

#	Si-Clause	Main Clause	Type
1	Si llueve (present indicative)	cancelaremos (future)	Real/possible — an open, plausible condition.
2	si yo fuera (imperfect subjunctive)	elegiría (simple conditional)	Hypothetical present — contrary to fact right now (I’m not the organizer).
3	Si hubiéramos revisado (pluperfect subjunctive)	habríamos elegido (compound conditional)	Hypothetical past — an unrealized past condition with a past-time result.
4	si hubiéramos planeado (pluperfect subjunctive)	tendríamos (simple conditional)	Mixed-time — a past condition (didn’t plan), a consequence felt right now (ahora).

Where to Go Next

• Chapter 34, El Condicional Simple — the simple conditional this chapter’s hypothetical-present and mixed-time main clauses both depend on.
• Chapter 35, El Futuro Compuesto & Condicional Compuesto — the compound conditional this chapter’s hypothetical-past main clause depends on, and the exact example this chapter’s central table reuses.
• Chapter 39, El Imperfecto de Subjuntivo — the imperfect subjunctive this chapter’s hypothetical-present si-clause depends on.
• Chapter 40, Compound Subjunctive — the pluperfect subjunctive this chapter’s hypothetical-past and mixed-time si-clauses both depend on.
• Chapter 38, El Presente de Subjuntivo: When to Use It — the broader subjunctive-vs-indicative decision framework this chapter’s si-clause logic is one specific, systematic application of.
• Chapter 57, Hedging, Emphasis & Pragmatic Particles — more softening and hypothetical-adjacent register strategies beyond the si-clause system itself.