Si Clauses: Spanish Conditionals Explained

Si clauses are conditional sentences — the “if…then” structures that let you talk about hypotheticals, real possibilities, and impossible scenarios. Spanish uses different tenses for each level of reality.

Three Types of Si Clauses

Type	Reality level	Si clause tense	Result clause tense
Real / Open	Likely or possible	Present indicative	Future or present
Hypothetical	Unlikely or imagined	Imperfect subjunctive	Conditional
Impossible	Contrary to past fact	Pluperfect subjunctive	Conditional perfect

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Type 1: Real Conditions (Present + Future)

These express genuine possibilities — things that can actually happen. No subjunctive needed.

Si + present indicative → future / present / imperative

• Si tienes tiempo, llámame. — If you have time, call me.
• Si llueve, no salimos. — If it rains, we don’t go out.
• Si estudias, aprobarás. — If you study, you’ll pass.
• Si estás cansado, descansa. — If you’re tired, rest.

This is also used for general truths:

• Si mezclas azul y amarillo, obtienes verde. — If you mix blue and yellow, you get green.

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Type 2: Hypothetical Conditions (Imperfect Subjunctive + Conditional)

These express scenarios that are unlikely, imagined, or contrary to present reality. This is the classic “if I were…” structure.

Si + imperfect subjunctive → conditional

• Si tuviera dinero, viajaría por el mundo. — If I had money, I’d travel the world. (I don’t have it.)
• Si fuera tú, no haría eso. — If I were you, I wouldn’t do that.
• Si pudiera, vendría contigo. — If I could, I’d come with you.
• Si viviera en París, hablaría francés cada día. — If I lived in Paris, I’d speak French every day.

The imperfect subjunctive has two forms (-ra and -se). The -ra form is more common:

• tuviera / tuviese → both correct; tuviera is more widely used

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Type 3: Impossible / Past Conditions (Pluperfect Subjunctive + Conditional Perfect)

These refer to the past — things that didn’t happen and can no longer happen. “If I had done X, I would have done Y.”

Si + pluperfect subjunctive → conditional perfect

• Si hubiera estudiado más, habría aprobado. — If I had studied more, I would have passed.
• Si hubieras llamado, habría venido. — If you had called, I would have come.
• Si hubiera sabido la verdad, no habría dicho nada. — If I had known the truth, I wouldn’t have said anything.

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Mixed Conditionals

Sometimes the condition is in the past but the result is in the present — or vice versa:

• Si hubiera estudiado medicina, sería médico ahora. — If I had studied medicine, I’d be a doctor now. (Past condition → present result)
• Si fuera más organizado, no habría perdido* el pasaporte.* — If I were more organised, I wouldn’t have lost my passport. (Present hypothetical → past result)

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What NOT to Use After Si

Never use the present subjunctive or the conditional after si in the “if” clause:

• Si tendría dinero… — Wrong
• Si tenga dinero… — Wrong
• Si tuviera dinero… — Correct

This is one of the most common errors. The conditional belongs in the result clause, not the si clause.

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Quick Reference

If (Si clause)	Then (Result clause)	Reality
Present indicative	Future / Present / Imperative	Real, possible
Imperfect subjunctive	Conditional	Hypothetical, unlikely
Pluperfect subjunctive	Conditional perfect	Impossible, past

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