Si Clauses: “If” Sentences in Spanish

Q: Can you use the conditional after si?

Not when si means "if": it's Si tuviera tiempo, never Si tendría tiempo. The only exception is when si means "whether": No sé si podría hacerlo ("I don't know whether I could do it").

Q: Should I use hubiera or habría?

After si, always hubiera: Si hubiera sabido…. In the other half, habría is the standard choice (…habría venido), but hubiera is also correct and very common in conversation (…hubiera venido).

Adapted from The Animated Book of Spanish, an interactive Spanish grammar book.

A si clause is the “if” half of a sentence: si tengo tiempo (if I have time). Which tense goes after si depends on how likely the situation is, so these are also called conditional sentences, or the first, second, and third conditionals.

General truthswhat always happens
si + present, then present
Si tengo tiempo, llamo a mi madre.If I have time, I call my mom.
Possiblefirst conditional
si + present, then future, present, or a command
Si tengo tiempo, llamaré a mi madre.If I have time, I’ll call my mom.
Unlikely or imaginarysecond conditional
si + past subjunctive, then conditional
Si tuviera tiempo, llamaría a mi madre.If I had time, I’d call my mom.
The past that didn’t happenthird conditional
si + hubiera + participle, then habría + participle
Si hubiera tenido tiempo, habría llamado a mi madre.If I had had time, I would have called my mom.

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General truths

For things that always happen when a condition is met, use the present in both halves. Here, si is close to whenever.

Si llueve, me quedo en casa.
If (whenever) it rains, I stay home.
Si mezclas rojo y azul, sale morado.
If you mix red and blue, you get purple.
Si mis hijos no duermen, están de mal humor.
If my kids don’t sleep, they’re in a bad mood.

Possible situations (the first conditional)

For something that could really happen, use si + the present. The other half can be the future, the present (more casual), or a command.

si + presentSi tengo tiempo,

futurete llamaré

If I have time, I’ll call youSi tengo tiempo, te llamaré.

Si llegas tarde, no te esperamos.
If you’re late, we won’t wait for you.
Si ves a Marta, dile que me llame.
If you see Marta, tell her to call me.
Si terminan pronto, podrán salir.
If they finish soon, they’ll be able to go out.

Unlikely or imaginary (the second conditional)

To imagine something that isn't true, or isn't likely, put the past subjunctive after si and the conditional in the other half.

si + past subjunctiveSi tuviera dinero,

conditionalcompraría una casa

If I had money, I would buy a houseSi tuviera dinero, compraría una casa.

Si yo fuera tú, no lo haría.
If I were you (but I'm not), I wouldn’t do it.
¿Qué harías si ganaras la lotería?
What would you do if you won the lottery?
Si viviéramos en la costa, iríamos a la playa todos los días.
If we lived on the coast (but we don't), we’d go to the beach every day.

The same situation can be possible or imaginary, depending on how likely you think it is:

Possible: presentUnlikely: past subjunctive
Possible: present
Si tengo tiempo, te llamo.
If I have time, I’ll call you.
Unlikely: past subjunctive
Si tuviera tiempo, te llamaría.
If I had time, I’d call you.
Possible: present
Si llueve, nos quedamos en casa.
If it rains, we’ll stay home.
Unlikely: past subjunctive
Si lloviera, nos quedaríamos en casa.
If it rained, we’d stay home.
Possible: present
Si vienes, lo pasaremos bien.
If you come, we’ll have fun.
Unlikely: past subjunctive
Si vinieras, lo pasaríamos bien.
If you came, we’d have fun.

The past that didn't happen (the third conditional)

To talk about how the past could have been different, use si + hubiera + the past participle, and habría + the participle in the other half.

si + hubiera + participleSi hubiera sabido,

habría + participlehabría venido

If I had known, I would have comeSi hubiera sabido, habría venido.

Only haber changes to match the person. The participle stays the same.

The forms of haber in third-conditional sentences: hubiera after si, habría in the other half
Subject	hubieraafter si	habríain the other half
yo	hubiera	habría
tú	hubieras	habrías
él / ella / usted	hubiera	habría
nosotros	hubiéramos	habríamos
vosotros	hubierais	habríais
ellos / ellas / ustedes	hubieran	habrían

Si hubieras estudiado, habrías aprobado.
If you had studied (but you didn't), you would have passed.
Si no hubiéramos perdido el tren, habríamos llegado a tiempo.
If we hadn’t missed the train (but we did), we would have arrived on time.
Si me lo hubieran dicho, no habría ido.
If they had told me (but they didn't), I wouldn’t have gone.

You can also mix them, when a past condition has a result now, or the other way around:

Si hubiera estudiado más, ahora tendría un trabajo mejor.
If I had studied more, I’d have a better job now.
Si fuera más organizado, no habría olvidado la reunión.
If I were more organized, I wouldn’t have forgotten the meeting.

Either half can go first

The si half can come first or second, and the tenses stay the same.

Si firstSi second
Si first
Si tengo tiempo, te llamo.
Si second
Te llamo si tengo tiempo.
I’ll call you if I have time.
Si first
Si pudiera, viajaría más.
Si second
Viajaría más si pudiera.
I’d travel more if I could.
Si first
Si hubiéramos salido antes, habríamos llegado.
Si second
Habríamos llegado si hubiéramos salido antes.
We would have made it if we’d left earlier.

Si meaning “whether”

After verbs like saber, preguntar, and no estar seguro, si means whether. The rules above don't apply here: any tense can follow, including the future and the conditional.

No sé si vendrá.
I don’t know if she’ll come.
Me preguntó si tenía hambre.
He asked me if I was hungry.
No sabíamos si llegarían a tiempo.
We didn’t know if they would make it on time.

Other ways to say “if”

A few other words and phrases set up a condition. Unlike si, most of them take the subjunctive.

en caso de quein case, if (subjunctive)
a menos queunless (subjunctive)
con tal de queas long as, provided that (subjunctive)
siempre queas long as (subjunctive)
comoif, as a warning (subjunctive)
de + infinitiveif, had (formal)
si nootherwise, if not

En caso de que llueva, llevamos paraguas.
In case it rains, we’ll bring umbrellas.
Como no estudies, vas a suspender.
If you don’t study, you’re going to fail.
De haberlo sabido, no habría venido.
Had I known, I wouldn’t have come.

Common mistakes English speakers make

Using the conditional after si
Incorrect:Si tendría tiempo, te llamaría.
Correct:Si tuviera tiempo, te llamaría.
The si half takes the past subjunctive. The conditional goes in the other half.
Using the present subjunctive after si
Incorrect:Si tengas tiempo, llámame.
Correct:Si tienes tiempo, llámame.
For possible situations, si takes the ordinary present.
Using the future after si
Incorrect:Si lloverá, no iremos.
Correct:Si llueve, no iremos.
The future only follows si when it means whether: No sé si lloverá.
Using habría after si
Incorrect:Si habría sabido, habría venido.
Correct:Si hubiera sabido, habría venido.
After si, it's always hubiera.
Mixing a possible and an unreal half
Incorrect:Si tuviera tiempo, te llamo.
Correct:Si tuviera tiempo, te llamaría.
When the si half is unreal (past subjunctive), the other half needs the conditional.

Questions about si clauses

What are si clauses in Spanish?

Sentences with si ("if"): one half sets a condition, and the other says what happens. The tense after si depends on how likely the condition is: Si tengo tiempo, te llamo (possible), Si tuviera tiempo, te llamaría (unlikely), Si hubiera tenido tiempo, te habría llamado (it didn't happen).

What are the three conditionals in Spanish?

The first conditional is for possible situations: si + present, then the present, future, or a command. The second is for unlikely or imaginary ones: si + past subjunctive, then the conditional. The third is for the past that didn't happen: si + hubiera + participle, then habría + participle.

Can you use the conditional after si?

Not when si means "if": it's Si tuviera tiempo, never Si tendría tiempo. The only exception is when si means "whether": No sé si podría hacerlo ("I don't know whether I could do it").

Does si take the subjunctive?

Never the present subjunctive. For possible situations, si takes the present indicative (si tienes). For unlikely or imaginary ones, it takes the past subjunctive (si tuvieras), and for the past that didn't happen, the pluperfect subjunctive (si hubieras tenido).

Should I use hubiera or habría?

After si, always hubiera: Si hubiera sabido…. In the other half, habría is the standard choice (…habría venido), but hubiera is also correct and very common in conversation (…hubiera venido).

Next upSaber vs. conocerTwo verbs for "to know": facts and skills vs. people and places, and what supe and conocí mean.

General truths

Possible situations (the first conditional)

Unlikely or imaginary (the second conditional)

The past that didn't happen (the third conditional)

Either half can go first

Si meaning “whether”

Other ways to say “if”

Common mistakes English speakers make

Using the conditional after si

Using the present subjunctive after si

Using the future after si

Using habría after si

Mixing a possible and an unreal half

Questions about si clauses

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