What tenses are used with si in French?

Three pairings. Si plus the present with a future result; si plus the imperfect with a conditional result; si plus the plus-que-parfait with a conditional perfect result. Si itself is never followed by a future or a conditional.

Why is si j'aurais wrong?

Because the conditional expresses a consequence, not a condition, so it belongs in the other clause. The correct form for a past hypothesis is si j'avais su, and for a present one si j'avais, with the conditional appearing only after the comma.

Does the imperfect after si refer to the past?

No. In si j'avais une voiture, the imperfect marks the condition as unreal, not as earlier. English does the same thing with its past tense in if I had a car, which is why the two languages line up neatly here.

Can si be followed by the future when it means whether?

Yes, and this is the one exception. Je ne sais pas s'il viendra is correct because that si means whether rather than if. The prohibition applies only to conditional si clauses.

What is the difference between si and quand?

Si presents the event as uncertain and takes the present tense; quand presents it as inevitable and takes the future. Si j'ai le temps means if I have time; quand j'aurai le temps means when I have time.

French grammar · Intermediate

Si Clauses in French: The Three Conditional Patterns and the One Forbidden Tense

Written by Camille Laurent, Lead French Curriculum Editor · Reviewed May 2026

A si clause states a condition and the other half of the sentence states its consequence. French locks the two halves together in three fixed pairings: si plus the present with the future, si plus the imperfect with the conditional, and si plus the plus-que-parfait with the conditional perfect. A future or a conditional can never follow si itself.

Si j'avais le temps, je viendrais avec toi.

If I had time, I'd come with you.

What it is

French conditionals work as matched pairs. Once you have chosen how real the condition is — likely, unlikely, or impossible because it is already past — both verb tenses are decided for you. The si clause carries the condition and never takes a future or a conditional; the other clause carries the result and is the only place those tenses can appear.

Si tu veux, on sort. Si tu voulais, on sortirait. Si tu avais voulu, on serait sortis. — If you want, we'll go out. If you wanted to, we'd go out. If you had wanted to, we'd have gone out.

How to spot it

Find the si and read the verb straight after it. Present means the condition is realistic, imperfect means it is hypothetical, plus-que-parfait means it never happened.

Si tu as faim, il y a du pain. — If you're hungry, there's bread.
Si j'étais riche, j'achèterais une maison au bord de la mer. — If I were rich, I'd buy a house by the sea.
Si elle avait su, elle ne serait jamais venue. — If she had known, she'd never have come.
S'il pleut demain, on annulera. — If it rains tomorrow, we'll cancel.

Si elides only in front of il and ils: s'il pleut, s'ils viennent. Before elle, on, and everything else it stays whole: si elle vient, si on part.

Si Clauses Conditionals Quick Reference

The three conditional patterns

Type	Si clause	Result clause	Example
Likely	présent	futur	Si j'ai le temps, je viendrai.
Likely (order)	présent	impératif	Si tu sors, ferme la porte.
General truth	présent	présent	Si on chauffe l'eau, elle bout.
Hypothetical	imparfait	conditionnel présent	Si j'avais le temps, je viendrais.
Impossible (past)	plus-que-parfait	conditionnel passé	Si j'avais eu le temps, je serais venu.
Mixed	plus-que-parfait	conditionnel présent	Si j'avais accepté, je serais riche.

Common Si Clauses Conditionals Examples in French

The three patterns in use, plus the mixed cases that fall between them:

Real Possibilities

Si tu finis tôt, appelle-moi.: If you finish early, call me.
Si le train est en retard, je te préviendrai.: If the train is late, I'll let you know.
Si vous avez des questions, n'hésitez pas.: If you have any questions, don't hesitate.
S'ils acceptent, nous signerons demain.: If they accept, we'll sign tomorrow.

The present after si covers anything the speaker treats as genuinely possible, including things that are almost certain.

Hypotheses and Daydreams

Si je gagnais au loto, j'arrêterais de travailler.: If I won the lottery, I'd stop working.
Si nous habitions plus près, on se verrait souvent.: If we lived closer, we'd see each other often.
Si tu étais à ma place, tu ferais quoi ?: If you were in my position, what would you do?
Si elle parlait mieux anglais, elle aurait ce poste.: If she spoke better English, she'd get that job.

The imperfect here is not a past tense. It marks the condition as unreal or unlikely, which is why French uses it for wishes and speculation.

Regrets About the Past

Si j'avais écouté mes parents, je n'aurais pas fait cette erreur.: If I'd listened to my parents, I wouldn't have made that mistake.
Si nous étions partis plus tôt, nous aurions eu le train.: If we'd left earlier, we'd have caught the train.
Si tu me l'avais dit, j'aurais pu t'aider.: If you'd told me, I could have helped you.
Si seulement il avait été là.: If only he had been there.

This pattern is the standard way of expressing regret in French, and si seulement leaves the result clause unsaid.

Mixed Time References

Si j'avais accepté ce poste, je vivrais à Berlin maintenant.: If I'd taken that job, I'd be living in Berlin now.
Si tu t'étais couché plus tôt, tu ne serais pas si fatigué.: If you'd gone to bed earlier, you wouldn't be so tired.
Si elle avait étudié le droit, elle serait avocate.: If she had studied law, she'd be a lawyer.

A past condition can have a present consequence. The si clause stays in the plus-que-parfait and the result clause moves to the present conditional.

How Si Clauses Work

One prohibition, three pairings, and a few points of word order account for the whole system.

No Future and No Conditional After Si

This is the rule that overrides everything else. Si takes the present, the imperfect, the passé composé, or the plus-que-parfait. Si j'aurai and si j'aurais are both impossible, however natural the English if I will and if I would feel.

Si tu viens demain, nous irons au marché.

If you come tomorrow, we'll go to the market.

Never si + -rai, never si + -rais.

The Tenses Come in Fixed Pairs

Present pairs with future, imperfect pairs with conditional present, plus-que-parfait pairs with conditional perfect. Each pair shifts the whole sentence one step further from reality, and the two halves always move together.

Si j'étais toi, je refuserais.

If I were you, I'd refuse.

imparfait ↔ conditionnel, always.

The Imperfect Marks Unreality, Not Past Time

Si j'avais une voiture does not describe the past. The imperfect is doing the same work as the English past in if I had a car: it distances the condition from what is actually true.

Si nous avions plus de place, on vous inviterait à dormir ici.

If we had more room, we'd invite you to stay over.

Imperfect after si means unlikely, not earlier.

Either Clause Can Come First

Si tu veux, on peut partir and on peut partir si tu veux mean the same thing. When the si clause comes first, a comma separates the two halves; when it comes second, no comma is needed.

Je viendrais volontiers si j'étais libre.

I'd gladly come if I were free.

Order is free, punctuation follows it.

An Imperative Can Replace the Future

In the realistic pattern, the result clause can be an order rather than a prediction. Si tu passes devant la boulangerie, prends du pain works exactly like si tu passes devant la boulangerie, tu prendras du pain, only more directly.

Si tu as un problème, dis-le-moi tout de suite.

If you have a problem, tell me straight away.

si + présent, then an imperative.

Common Mistakes with Si Clauses Conditionals

Incorrect: Si j'aurai le temps, je viendrai. — If I have time, I'll come.

Correct: Si j'ai le temps, je viendrai. — If I have time, I'll come.

The future is banned after si. The condition goes in the present and the future stays in the result clause, where it belongs.

Incorrect: Si j'aurais su, je ne serais pas venu. — If I'd known, I wouldn't have come.

Correct: Si j'avais su, je ne serais pas venu. — If I'd known, I wouldn't have come.

The conditional is banned after si too. For a past condition, si takes the plus-que-parfait and the conditional perfect goes in the other half.

Incorrect: Si j'étais riche, j'achèterai un bateau. — If I were rich, I'd buy a boat.

Correct: Si j'étais riche, j'achèterais un bateau. — If I were rich, I'd buy a boat.

The two halves have to match. An imperfect condition requires a conditional result, so the -s of the conditional ending is not optional here.

Incorrect: Il parle comme s'il sait tout. — He talks as if he knows everything.

Correct: Il parle comme s'il savait tout. — He talks as if he knows everything.

Comme si always takes the imperfect or the plus-que-parfait, whatever tense the main clause is in, because it presents the comparison as counterfactual.

The Three Patterns Conjugated in Full

The same idea — having time, and coming — run through all three patterns, so you can see exactly which forms change.

Pattern One: Présent and Futur

A condition presented as realistic. The result clause takes the futur simple.

Pronoun	si clause	result clause
je / j'	si j'ai le temps	je viendrai
tu	si tu as le temps	tu viendras
il / elle / on	s'il a le temps	il viendra
nous	si nous avons le temps	nous viendrons
vous	si vous avez le temps	vous viendrez
ils / elles	s'ils ont le temps	ils viendront

Si elides before il and ils and nowhere else, so si elle a le temps keeps both words whole.

Pattern Two: Imparfait and Conditionnel

A condition presented as unlikely or contrary to fact. Note that the two verb forms differ only in the final syllable.

Pronoun	si clause	result clause
je / j'	si j'avais le temps	je viendrais
tu	si tu avais le temps	tu viendrais
il / elle / on	s'il avait le temps	il viendrait
nous	si nous avions le temps	nous viendrions
vous	si vous aviez le temps	vous viendriez
ils / elles	s'ils avaient le temps	ils viendraient

The conditional is the future stem viendr- with imperfect endings, which is why the result clause looks like a blend of the two.

Pattern Three: Plus-Que-Parfait and Conditionnel Passé

A condition that can no longer be met. Venir takes être, so its conditional perfect agrees with the subject.

Pronoun	si clause	result clause
je / j'	si j'avais eu le temps	je serais venu(e)
tu	si tu avais eu le temps	tu serais venu(e)
il / elle / on	s'il avait eu le temps	il serait venu
nous	si nous avions eu le temps	nous serions venu(e)s
vous	si vous aviez eu le temps	vous seriez venu(e)(s)
ils / elles	s'ils avaient eu le temps	ils seraient venus

Both halves are compound tenses here, which is what makes this the longest pattern to say out loud.

The Other Jobs of Si

Not every si introduces a condition, and the tense rules only apply to the ones that do.

Si meaning whether

After verbs of asking, knowing, and wondering, si means whether. This si is not conditional, so the future and the conditional are perfectly allowed after it.

Je ne sais pas s'il viendra.: I don't know whether he'll come.
Elle m'a demandé si je serais là.: She asked whether I'd be there.
Je me demande si ça marcherait.: I wonder whether that would work.

This is the one place si and a future can share a clause, and it is a genuine exception rather than a loophole.

Si with no result clause

Si can stand alone to make a suggestion or express a wish, with the consequence left implied.

Si on allait au cinéma ?: How about going to the cinema?
Si seulement je pouvais recommencer.: If only I could start again.
Et si tu lui écrivais ?: What if you wrote to him?

Si on plus the imperfect is one of the most common ways of proposing something in spoken French.

Même si and comme si

Même si means even if and follows the ordinary si rules. Comme si means as if and always takes the imperfect or the plus-que-parfait, never the present.

Même s'il pleut, nous sortirons.: Even if it rains, we'll go out.
Il parle comme s'il savait tout.: He talks as if he knew everything.
Elle m'a regardé comme si elle ne m'avait jamais vu.: She looked at me as if she'd never seen me before.

Comme si is fixed: comme s'il sait is wrong even when the main verb is in the present.

Si Clauses Conditionals FAQs

What tenses are used with si in French?: Three pairings. Si plus the present with a future result; si plus the imperfect with a conditional result; si plus the plus-que-parfait with a conditional perfect result. Si itself is never followed by a future or a conditional.
Why is si j'aurais wrong?: Because the conditional expresses a consequence, not a condition, so it belongs in the other clause. The correct form for a past hypothesis is si j'avais su, and for a present one si j'avais, with the conditional appearing only after the comma.
Does the imperfect after si refer to the past?: No. In si j'avais une voiture, the imperfect marks the condition as unreal, not as earlier. English does the same thing with its past tense in if I had a car, which is why the two languages line up neatly here.
Can si be followed by the future when it means whether?: Yes, and this is the one exception. Je ne sais pas s'il viendra is correct because that si means whether rather than if. The prohibition applies only to conditional si clauses.
What is the difference between si and quand?: Si presents the event as uncertain and takes the present tense; quand presents it as inevitable and takes the future. Si j'ai le temps means if I have time; quand j'aurai le temps means when I have time.