Si-clauses in French: the 3 patterns, no exceptions, with examples

Si-clauses are the single most-tested grammar structure across DELF, TEF Canada, TCF, AP French, GCSE Higher tier, and A-Level. They're also where most English speakers consistently lose points by sliding a conditional after si.

Here's the entire structure in one article. There are exactly 3 patterns. There are zero exceptions. Once you internalize them, you stop making the most common B1/B2 grammar error.

The 3 patterns

The pattern is determined by how real the condition is:

That's the whole system. Memorize these three rows.

Pattern 1: Si + présent + futur simple

For real conditions in the future. The condition is plausible; the result follows.

Si je gagne au loto, je partirai en vacances. If I win the lottery, I'll go on holiday.

S'il pleut demain, nous resterons à la maison. If it rains tomorrow, we'll stay home.

Si tu travailles dur, tu réussiras. If you work hard, you'll succeed.

Allowed variant: the main clause can also be présent (general truth) or impératif (instruction):

Si tu as froid, ferme la fenêtre. If you're cold, close the window. (impératif)

S'il fait beau, je suis content. If the weather is nice, I'm happy. (présent, habitual)

Pattern 2: Si + imparfait + conditionnel présent

For hypothetical situations in the present or future, things that aren't true now but you're imagining as if they were.

Si j'étais riche, j'achèterais une maison à Paris. If I were rich, I would buy a house in Paris.

Si tu avais le temps, on irait au cinéma. If you had time, we would go to the movies.

S'il pleuvait moins, nous pourrions sortir. If it rained less, we could go out.

Critical: the si-clause is imparfait, not subjunctive (unlike old-fashioned English "if I were"). French treats this as past tense form. Yes, French uses the past tense to express a hypothetical present. Just memorize the pattern; don't try to map it onto English grammar.

Pattern 3: Si + plus-que-parfait + conditionnel passé

For hypothetical situations in the past, things that didn't happen, but you're imagining what would have happened if they had.

Si j'avais su, je serais venu plus tôt. If I had known, I would have come earlier.

Si tu avais étudié, tu aurais réussi l'examen. If you had studied, you would have passed the exam.

S'il n'avait pas plu, nous serions sortis. If it hadn't rained, we would have gone out.

This pattern is heavily used in regret, hindsight, what-if narratives. DELF B2 essay prompts frequently invite it ("Si vous aviez le choix, qu'auriez-vous fait différemment?").

The error that fails everyone

✗ Si j'aurais su, je serais venu plus tôt.

This sentence is wrong because aurais is conditionnel and the si-clause never takes conditionnel. The correct form uses plus-que-parfait in the si-clause:

✓ Si j'avais su, je serais venu plus tôt.

This single error is the most-flagged French grammar mistake on DELF B2, AP French, A-Level, and TEF Canada. French native speakers consider "si j'aurais" as ungrammatical as English speakers consider "I done it" or "ain't got no". It marks the speaker as untrained.

The rule, simplified: in the si-clause, no conditionnel and no futur. Ever.

How to drill the patterns to reflex

The shortcut: build 10 personal example sentences per pattern, with your own life details. Personal = sticky.

For Pattern 1

If I save 100€ this month, I'll buy a new keyboard. If it doesn't rain tomorrow, I'll go cycling. If I finish work early on Friday, we'll go to dinner.

For Pattern 2

If I were on holiday right now, I would be at the beach. If I had more time, I would learn Spanish too. If my apartment were bigger, I would adopt a dog.

For Pattern 3

If I had studied harder in college, I would have gone to grad school. If we had bought tickets earlier, we would have gone to the concert. If I hadn't taken that job, I wouldn't have met my partner.

Write 30 sentences total. Read them aloud daily for a week. The patterns become reflexive within 10 days of consistent practice.

What gets tested where

If you're sitting any of these and you can't produce all three patterns correctly in writing under time pressure, you're leaking points unnecessarily.

Edge cases

Multiple conditions in one sentence

Si j'avais le temps et si tu venais avec moi, on irait à Paris. If I had the time and if you came with me, we'd go to Paris.

Both si-clauses use the same tense (imparfait). The main clause uses the matching conditionnel.

"Si" not introducing a condition

Si can also mean "whether" in indirect questions. In that case, normal tense rules apply, no special pattern.

Je ne sais pas s'il viendra. I don't know whether he'll come. (futur simple OK here, because si = whether, not if)

Reversed order

The clauses can swap. The pattern stays the same.

Je serais venu si j'avais su. I would have come if I had known.

J'achèterais une maison si j'étais riche. I would buy a house if I were rich.

Tool to drill the patterns

The si-clause patterns are mostly about producing conditionnel and plus-que-parfait forms correctly under time pressure. Both tenses are in the Bonjour Verbs drill set, with strict accent checking and stepwise feedback when you miss a stem or ending. Free tier covers 200+ verbs across both tenses.

For exam-specific drills calibrated to your target level, see the DELF B2 guide (the level where si-clauses become critical), or the TEF Canada guide for the immigration audience.