Conditional Sentences: Comprehensive Guide

Complete guide to Spanish conditional sentences with all types and verb mood combinations.

Type 1: Real/Possible Conditions (Present/Future)

If something happens, something else will happen

Pattern: Si + present indicative, present/future indicative

Si llueve, no voy. (If it rains, I won't go.) Si estudias, aprobarás. (If you study, you will pass.) Si tienes tiempo, llámame. (If you have time, call me.)

Type 2: Hypothetical (Present)

If something were to happen (but it's not happening)...

Pattern: Si + imperfect subjunctive, conditional

Si tuviera dinero, compraría un coche. (If I had money, I would buy a car.) Si fuera rico, viajaría mucho. (If I were rich, I would travel a lot.) Si pudiera, te ayudaría. (If I could, I would help you.)

Type 3: Hypothetical (Past)

If something had happened (but it didn't)...

Pattern: Si + pluperfect subjunctive, conditional perfect

Si hubiera estudiado, habría aprobado. (If I had studied, I would have passed.) Si hubieras venido, te habría visto. (If you had come, I would have seen you.) Si hubiera sabido, no habría ido. (If I had known, I wouldn't have gone.)

Imperfect Subjunctive Forms

Two forms (both correct):

• tuviera / tuviese
• fuera / fuese
• pudiera / pudiese

Si tuviera/tuviese dinero... (If I had money...)

Mixed Conditionals

Mixing time frames:

Past condition, present result: Si hubiera estudiado, ahora sería médico. (If I had studied, I would be a doctor now.)

Present condition, past result: Si fuera más cuidadoso, no habría perdido las llaves. (If I were more careful, I wouldn't have lost the keys.)

Como Si (As If)

Always uses imperfect or pluperfect subjunctive:

Habla como si lo supiera. (He talks as if he knew.) Actúa como si fuera el jefe. (He acts as if he were the boss.) Habla como si hubiera estado allí. (He talks as if he had been there.)

De + Infinitive (Literary)

Replaces si clause in formal writing:

De tener dinero, compraría un coche. (If I had money, I would buy a car.) De haberlo sabido, no habría ido. (Had I known, I wouldn't have gone.)

Unless (A menos que)

Always requires subjunctive:

Iré a menos que llueva. (I'll go unless it rains.) No vendré a menos que me invites. (I won't come unless you invite me.)

Provided That (Con tal de que)

Requires subjunctive:

Iré con tal de que vengas tú también. (I'll go provided that you come too.) Lo haré con tal de que me pagues. (I'll do it provided that you pay me.)

In Case (En caso de que)

Requires subjunctive:

Lleva paraguas en caso de que llueva. (Bring an umbrella in case it rains.) Te llamo en caso de que haya problemas. (I'll call you in case there are problems.)

Without (Sin que)

Requires subjunctive:

Salió sin que lo viera. (He left without my seeing him.) No puedes entrar sin que te inviten. (You can't enter without being invited.)

Common Errors

❌ Si tendría dinero... ✓ Si tuviera dinero...

❌ Si habría sabido... ✓ Si hubiera sabido...

Never use conditional or future after "si" in conditional sentences.

Time Clauses vs Conditional

Cuando (when - certainty): Cuando llueva, no saldré. (When it rains, I won't go out.)

Si (if - uncertainty): Si llueve, no saldré. (If it rains, I won't go out.)

Other Conditional Expressions

Siempre que (as long as/provided that): Iré siempre que pueda. (I'll go as long as I can.)

A no ser que (unless): Vendré a no ser que esté enfermo. (I'll come unless I'm sick.)

Conditional Without Si

Can be implied:

Con más dinero, compraría un coche. (With more money, I would buy a car.) En tu lugar, no iría. (In your place, I wouldn't go.)

Summary Table

Practice