Si clauses in Spanish: the chart
Ask how real the condition is. If it can come true — now, later, or whenever it was true in the past — si takes the indicative: si tengo tiempo, si llueve, si no hacías lo que decía. If it is unlikely, imagined or simply not true now, si takes the imperfect subjunctive and the other half takes the conditional: si tuviera tiempo, te llamaría. If it is a past that did not happen, si takes the pluperfect subjunctive: si hubiera tenido tiempo, te habría llamado.
English gives a quick test, because it shifts its tenses the same way. If I have becomes si tengo; if I had, meaning now or later, becomes si tuviera; if I had had becomes si hubiera tenido. And would becomes the conditional in the other half: I would call is te llamaría, I would have called is te habría llamado.
| If it is… | After si | The other half |
|---|---|---|
| possible | si tengo tiempo, | te llamo / te llamaré |
| possible, in the past | si no hacías lo que decía, | se enfadaba |
| unlikely, or not true now | si tuviera tiempo, | te llamaría |
| a past that did not happen | si hubiera tenido tiempo, | te habría llamado |
| a past, with a result now | si hubiera terminado, | hoy tendría un trabajo mejor |
Si tengo: a condition that can come true
When the condition can come true, si takes the indicative — the present, the present perfect, a past tense — and never the future or the conditional: si tengo tiempo, not si tendré tiempo. The future goes in the other half: si tengo tiempo, te llamaré. English works the same way — if I have time, never if I will have time — so the slip, si tendré, comes from reaching for will.
The other half takes the indicative or a command: si llueve, me quedo en casa; si llueve, me quedaré en casa; si vas a salir, ponte el abrigo.
A real condition can sit in the past, too, for something that happened whenever it was true: si no hacías lo que él decía, se enfadaba — if you didn't do what he said, he got angry.
In legal and administrative Spanish you will still meet an old future subjunctive after si — si no se presentare el escrito en el plazo indicado… The academies call it archaic; administrative language still keeps it.
| English | Spanish |
|---|---|
| If I have time, I'll call you. | Si tengo tiempo, te llamo. |
| If it rains, I'll stay at home. | Si llueve, me quedaré en casa. |
| If you're going out, put your coat on. | Si vas a salir, ponte el abrigo. |
| If you've finished, you can go. | Si has terminado, puedes irte. |
| If you didn't do what he said, he got angry. | Si no hacías lo que él decía, se enfadaba. |
Si tuviera: unlikely, imagined, or not true now
When the condition is unlikely, imagined or not true now, si takes the imperfect subjunctive and the other half takes the conditional: si tuviera tiempo, te llamaría; si me tocara la lotería, me compraría un coche.
The imperfect subjunctive has two forms, and both are right everywhere: si tuviera or si tuviese, si fuera or si fuese, si me tocara or si me tocase.
The conditional never goes after si. Si tendría dinero, me compraría un coche is the academies' own example of what to avoid: they record it among speakers in the Basque Country and the regions around it — Navarra, Burgos, Cantabria and La Rioja — and in some parts of the Americas, and advise against it.
In the other half, the conditional is the standard form. Everyday speech often puts the imperfect there instead — si me tocara la lotería, me compraba un coche — and in parts of Central America and the Caribbean an old -ra form survives: si pudiera, lo hiciera, which the academies now call archaic.
Leave the other half out and si + the imperfect subjunctive is a wish: ¡si pudiera convencerlo! — if only I could convince him.
| English | Spanish |
|---|---|
| If I won the lottery, I'd buy a car. | Si me tocara la lotería, me compraría un coche. |
| If I were you, I wouldn't do it. | Si yo fuera tú, no lo haría. |
| If I had more time, I'd learn the piano. | Si tuviera más tiempo, aprendería a tocar el piano. |
| If she knew, she'd be angry. | Si lo supiera, se enfadaría. |
| If only I could! | ¡Si pudiera! |
Si hubiera tenido: a past that did not happen
For a past that did not happen, si takes the pluperfect subjunctive — hubiera or hubiese with the participle: si lo hubiera sabido, si hubieras estudiado.
The other half has three forms, and the academies accept all three: the conditional perfect (te lo habría dicho), the pluperfect subjunctive itself (te lo hubiera dicho — the -ra form preferred, the -se form admitted) and, when the result is now, the plain conditional (hoy tendría un trabajo mejor).
So hubiera and habría swap only in the other half. After si it is always hubiera or hubiese: si lo habría sabido is the same slip as si tendría, one tense back, and the academies advise against it among the same speakers — in the north of Spain and parts of the Americas.
| English | Spanish |
|---|---|
| If I had known, I would have told you. | Si lo hubiera sabido, te lo habría dicho. |
| If you had studied, you would have passed. | Si hubieras estudiado, habrías aprobado. |
| If I had had money, I would have bought a car. | Si hubiera tenido dinero, me hubiera comprado un coche. |
| If I had finished my degree, I'd have a better job today. | Si hubiera terminado los estudios, hoy tendría un trabajo mejor. |
Si or whether? The si that takes any tense
Not every si is an if. After a verb like saber, preguntar, decir or enterarse, si means whether — an indirect question — and then any tense fits, the future and the conditional included: no sé si vendrá, no me dijo si iría o no a la fiesta. The rule against the future belongs to the si of a condition only. If whether fits in English, any tense can follow.
The comma follows the order. A si clause that comes first is set off with one — si no hay mucho tráfico, llegarán a las dos; at the end it normally takes none — llegarán a las dos si no hay mucho tráfico. A very short one in front can drop it: si lo sé no vengo.
And the spelling: the conjunction si has no accent. Sí, with one, is yes.
| English | Spanish |
|---|---|
| I asked him if he knew where you lived. | Le pregunté si sabía dónde vivías. |
| He didn't tell me whether he'd come to the party. | No me dijo si iría o no a la fiesta. |
| I don't know whether she'll come. | No sé si vendrá. |
Como si, siempre que, en caso de que: the other ways to say if
Como si is as if, and the subjunctive follows it — the imperfect for now, the pluperfect for before: habla como si fuera el jefe, hizo como si no lo hubiese visto.
Como on its own can set a condition too, with the subjunctive: como no estudies más, no aprobarás — the academies' own example.
Siempre que has two jobs. With the indicative it is whenever: siempre que puedo, vengo. As a condition — as long as — it always takes the subjunctive: te lo dejo, siempre que me lo devuelvas. Siempre y cuando means only as long as, and always takes the subjunctive too.
En caso de que keeps its de: en caso de que llueva, never en caso que.
| English | Spanish |
|---|---|
| as if | como si: Habla como si fuera el jefe. |
| if | como: Como no estudies más, no aprobarás. |
| as long as | siempre que, siempre y cuando: Te lo dejo, siempre que me lo devuelvas. |
| in case | en caso de que: En caso de que llueva, lo dejamos para mañana. |
Why do English speakers get Spanish if sentences wrong?
Because English hides the subjunctive. If I had time, meaning now, looks like a plain past tense, so it comes out si tenía tiempo — which in Spanish is a real condition in the past, whenever I had time — or, reaching for would, si tendría tiempo. If I had known looks like a past perfect and comes out si había sabido or si habría sabido for si hubiera sabido. And will slips in after si: si tendré tiempo for si tengo tiempo.
Our own grading shows how hard the two forms of the unlikely if are. Nivelo grades every conversation turn, writing task and test item against a grammar point; counted on 24 September 2026 over 70 Spanish learners and 6,959 graded attempts (our own accounts excluded), the conditional — the would-form an unlikely if needs in its other half — was wrong 48% of the time (14 learners, 136 attempts; 42% at B2), and the imperfect subjunctive 57% (8 learners, 37 attempts; 58% at B2). The if-sentences themselves have too few graded attempts yet to rate on their own, so the quiz is the measure for those.
What comes after si clauses?
The present subjunctive is the same mood in the present — quiero que vengas, cuando llegue, para que lo entiendas — and the imperfect subjunctive here is its past. Preterite vs imperfect is the choice inside a real if in the past: si no hacías lo que decía. The conditional sentence said without thinking is the grammar line between B1 and B2: B1 vs B2 Spanish says what else changes there, and how to go from B1 to B2 is the plan. The future tense is the other half of a real if — si tengo tiempo, iré — and its twelve short stems are the conditional's too: tendría, podría, diría. The conditional has the rest of that tense, and the English would it does not cover. And if more time would mean the piano, the verb is tocar: jugar, tocar or poner sorts the Spanish verbs for play. The free Spanish level test places you on the A1–C2 scale in five minutes.