Si Clauses & Conditional Sentences

Introduction

"If" sentences (oraciones condicionales) are essential for expressing possibilities, hypotheticals, and regrets. Spanish has three main types, each with specific tense combinations. Getting them right is a major milestone in fluency.

Type 1: Real / Possible Conditions

If X happens, Y will happen. (Likely or habitual situations)

Structure: Si + present indicative → present / future / imperative

Future Result

• Si llueve, me quedaré en casa. — If it rains, I'll stay home.
• Si estudias, aprobarás el examen. — If you study, you'll pass the exam.
• Si tiene tiempo, vendrá. — If she has time, she'll come.

Present / Habitual Result

• Si como mucho, me siento mal. — If I eat a lot, I feel bad. (habitual)
• Si no duermes, estás cansado. — If you don't sleep, you're tired.

Imperative Result

• Si tienes hambre, come algo. — If you're hungry, eat something.
• Si no entiendes, pregunta. — If you don't understand, ask.

Key rule: NEVER use the subjunctive after si in Type 1. It's always indicative. Si llueve… (NOT: Si llueva…)

Type 2: Hypothetical / Unlikely Conditions

If X happened (but it probably won't), Y would happen.

Structure: Si + imperfect subjunctive → conditional

• Si tuviera dinero, viajaría por el mundo. — If I had money, I would travel the world.
• Si hablara español, conseguiría ese trabajo. — If I spoke Spanish, I would get that job.
• Si fuera tú, no lo haría. — If I were you, I wouldn't do it.
• Si pudiera, te ayudaría. — If I could, I would help you.
• Si ganara la lotería, compraría una casa. — If I won the lottery, I would buy a house.

Two forms of imperfect subjunctive: Both -ra and -se forms work: Si tuviera… = Si tuviese…. The -ra form is more common in conversation.

Common Phrases

• Si yo fuera tú… — If I were you…
• Si pudiera elegir… — If I could choose…
• Si no fuera por ti… — If it weren't for you…

Type 3: Impossible / Past Conditions (Regrets)

If X had happened (but it didn't), Y would have happened.

Structure: Si + pluperfect subjunctive → conditional perfect

• Si hubiera estudiado, habría aprobado. — If I had studied, I would have passed.
• Si hubieras venido, te habrías divertido. — If you had come, you would have had fun.
• Si hubiera sabido, no habría ido. — If I had known, I wouldn't have gone.
• Si nos hubiéramos conocido antes… — If we had met each other sooner…

Alternative: The -ra form of the pluperfect subjunctive can replace the conditional perfect in the result clause: Si hubiera estudiado, hubiera aprobado. (This is common in speech.)

Quick Reference

Mixed Conditionals

Sometimes the si-clause is about the past but the result is about the present (or vice versa):

• Si hubiera estudiado medicina, ahora sería médico. — If I had studied medicine, I would now be a doctor. (past condition → present result)
• Si fuera más valiente, habría dicho algo. — If I were braver, I would have said something. (present condition → past result)

What NEVER Follows "Si"

Si is NEVER followed by the present subjunctive or the conditional:

• Si llueva… → Si llueve…
• Si tendría dinero… → Si tuviera dinero…

These are two of the most common errors learners make.

Practice