Spanish Si Clauses Made Simple: Your Guide to “If-Then” Sentences

By SpanishGram

Have you ever wanted to say “If I have time, I will go” or “If I had money, I would travel” in Spanish? These “if-then” sentences are called si clauses, and they’re easier to master than you might think!

💡 Grammar Connection: Mastering si clauses requires understanding both the imperfect subjunctive AND the conditional tense. If you need to review how to form “would,” “could,” or “should” in Spanish, visit our conditional tense guide for a comprehensive refresher.

What Are Si Clauses?

Si clauses are conditional sentences that express what would happen if certain conditions were met. They always have two parts:

  • The condition (starts with “si” – if)
  • The result (what happens when the condition is met)

The Two Main Types You Need to Know

Type 1: Real Possibilities (Present + Future)

Use when: Talking about things that could really happen

Pattern: Si + present tense → future tense

Examples:

  • Si tengo tiempo, iré al cine. (If I have time, I will go to the movies)
  • Si llueve, no saldremos. (If it rains, we won’t go out)
  • Si estudias, aprobarás el examen. (If you study, you will pass the exam)

Think of it as: “If this happens now → this will happen later”

Type 2: Hypothetical Situations (Imperfect Subjunctive + Conditional)

Use when: Imagining unreal or unlikely situations

Pattern: Si + imperfect subjunctive → conditional

Examples:

  • Si tuviera dinero, viajaría por el mundo. (If I had money, I would travel the world)
  • Si fuera más alto, jugaría al baloncesto. (If I were taller, I would play basketball)
  • Si pudiera volar, visitaría todos los países. (If I could fly, I would visit all countries)

Think of it as: “If this were true (but it’s not) → this would happen”

Important Note: If you need a refresher on how to form the conditional tense (the “would” part of these sentences), check out our complete guide to the Spanish conditional tense for detailed explanations and examples.

Simple Rules to Remember

Rule 1: Never Use Future After “Si”

❌ Si tendré tiempo, iré contigo. (WRONG!)
✅ Si tengo tiempo, iré contigo. (CORRECT!)

Rule 2: Match the Tenses Correctly

  • Real situations: Present → Future
  • Hypothetical situations: Imperfect Subjunctive → Conditional

Rule 3: The “Si” Clause Always Comes First

But you can flip them if you want:

  • Si estudio, aprobaré. OR Aprobaré si estudio.

Real-Life Examples You’ll Actually Use

Making Plans:

  • Si hace buen tiempo, iremos a la playa. (If the weather is nice, we’ll go to the beach)
  • Si llegas temprano, podemos tomar un café. (If you arrive early, we can have coffee)

Giving Advice:

  • Si estudiaras más, sacarías mejores notas. (If you studied more, you would get better grades)
  • Si hicieras ejercicio, te sentirías mejor. (If you exercised, you would feel better)

Dreaming Big:

  • Si ganara la lotería, compraría una casa en la playa. (If I won the lottery, I would buy a beach house)
  • Si pudiera hablar todos los idiomas, viajaría por todo el mundo. (If I could speak all languages, I would travel the whole world)

Common Mistakes and How to Avoid Them

Mistake 1: Mixing the Patterns

❌ Si tendría dinero, viajaría. (mixing conditional in both parts)
✅ Si tuviera dinero, viajaría. (imperfect subjunctive + conditional)

Mistake 2: Using Present for Hypotheticals

❌ Si soy rico, compro un yate. (sounds like you might be rich!)
✅ Si fuera rico, compraría un yate. (clear it’s hypothetical)

Mistake 3: Forgetting Irregular Verbs

❌ Si podía, te ayudaba. (wrong verb forms)
✅ Si pudiera, te ayudaría. (correct imperfect subjunctive + conditional)

Your Quick Decision Guide

SituationPatternExample
Real future plansPresent → FutureSi voy, te llamaré
Possible outcomesPresent → FutureSi estudias, aprobarás
Giving adviceImperfect Subjunctive → ConditionalSi estudiaras, aprobarías
Impossible dreamsImperfect Subjunctive → ConditionalSi volara, iría a la luna
Current habitsPresent → PresentSi tengo hambre, como

Key Irregular Verbs in Imperfect Subjunctive

Must-Know Irregulars:

  • Tener → tuviera/tuviese
  • Poder → pudiera/pudiese
  • Querer → quisiera/quisiese
  • Saber → supiera/supiese
  • Venir → viniera/viniese
  • Hacer → hiciera/hiciese
  • Decir → dijera/dijese
  • Ser → fuera/fuese
  • Ir → fuera/fuese
  • Ver → viera/viese

Practice Exercises

Test your understanding:

  1. Complete: “Si ______ (tener) tiempo, te ______ (ayudar).”
    • Answer: tengo, ayudo (present + present for current habit)
    • OR: tuviera, ayudaría (imperfect subjunctive + conditional for hypothetical)
  2. Choose: “Si (llueve/lloviera) mañana, no (iremos/iríamos) al parque.”
    • Answer: llueve, iremos (real possibility)
  3. Translate: “If I were you, I would study more.”
    • Answer: Si fuera tú, estudiaría más.

Ready to Test Your Skills?

Take our Spanish Si Clauses Quiz to practice what you’ve learned with instant feedback and detailed explanations!

Quick Tips for Success

  1. Real = Present → Future
  2. Hypothetical = Imperfect Subjunctive → Conditional
  3. Never use future after “si”
  4. Learn the key irregular verbs
  5. Practice with sentences you’d actually use

When You’ll Use Si Clauses

  • Making plans with friends
  • Giving advice to someone
  • Talking about your dreams
  • Discussing possibilities at work
  • Making polite suggestions

Next Steps

Want to continue mastering Spanish grammar? Check out our other Spanish grammar guides or explore our complete DELE B1 preparation materials.

Remember: even native speakers practice these patterns. You’re doing great! 🌟


Learning Tip: Try creating your own si clauses about your daily life. For example: “Si termino mi trabajo temprano, veré una película” (If I finish work early, I’ll watch a movie). This makes the grammar feel practical and memorable!