Si Clauses: An Introduction

Si (if) clauses — also called oraciones condicionales — are used to express conditions and their results. In this lesson, we focus primarily on Type 1 (real/possible) conditions and introduce the concept of Type 2 (unreal/hypothetical) conditions.

Overview of Conditional Sentence Types

Spanish has three main types of conditional sentences:

Type	Condition	Reality	Si clause	Result clause
Type 1	Real / Possible	Likely to happen	Si + present	present / future / imperative
Type 2	Unreal / Hypothetical	Unlikely or contrary to fact	Si + imperfect subjunctive	conditional
Type 3	Impossible / Past	Didn't happen	Si + pluperfect subjunctive	conditional perfect

In this lesson: We will master Type 1 and introduce the concept of Type 2. Types 2 and 3 require the subjunctive mood, which is covered in more advanced courses.

Type 1: Real / Possible Conditions

These express situations that are realistic and possible. The condition might very well be true or become true.

Structure

Si + present indicative, + present / future / imperative

The si clause uses the present tense. The result clause can use:

The present tense (for general truths or habits)
The future tense (for specific future outcomes)
The imperative (for commands or instructions)

Pattern A: Si + Present, Present

Used for general truths, habits, or automatic results:

Spanish	English
Si llueve, me quedo en casa.	If it rains, I stay at home.
Si no comes, tienes hambre.	If you don't eat, you get hungry.
Si estudias mucho, aprendes rápido.	If you study a lot, you learn quickly.
Si hace frío, me pongo un abrigo.	If it's cold, I put on a coat.
Si no duermo bien, estoy cansado todo el día.	If I don't sleep well, I'm tired all day.

Tip: This pattern is similar to the English "zero conditional" — it describes things that are always or generally true.

Pattern B: Si + Present, Future

Used for specific predictions about the future:

Spanish	English
Si llueve mañana, no saldremos.	If it rains tomorrow, we won't go out.
Si estudias, aprobarás el examen.	If you study, you will pass the exam.
Si tengo tiempo, iré al gimnasio.	If I have time, I will go to the gym.
Si no llegas a tiempo, perderás el tren.	If you don't arrive on time, you'll miss the train.
Si me invitan, iré a la fiesta.	If they invite me, I will go to the party.
Si ahorramos dinero, podremos comprar un coche.	If we save money, we will be able to buy a car.

You can also use ir + a + infinitive in the result clause:

Spanish	English
Si hace buen tiempo, vamos a ir a la playa.	If the weather's nice, we're going to go to the beach.
Si no vienes, voy a ir solo.	If you don't come, I'm going to go alone.

Pattern C: Si + Present, Imperative

Used for instructions, advice, or commands:

Spanish	English
Si tienes hambre, come algo.	If you're hungry, eat something.
Si no entiendes, pregunta al profesor.	If you don't understand, ask the teacher.
Si ves a María, dile que me llame.	If you see María, tell her to call me.
Si necesitas ayuda, llámame.	If you need help, call me.
Si terminas pronto, ven a mi casa.	If you finish early, come to my house.

Word Order

The si clause can come first or second in the sentence. When it comes first, a comma separates the clauses:

Si clause first	Result clause first
Si llueve, me quedo en casa.	Me quedo en casa si llueve.
Si estudias, aprobarás.	Aprobarás si estudias.
Si tienes frío, cierra la ventana.	Cierra la ventana si tienes frío.

Note: Both word orders are equally correct and natural.

Important Rule: Never Use the Present Subjunctive or Future After Si

In Spanish, you cannot use the future tense or the present subjunctive directly after si in conditional sentences:

Si Clauses Introduction