FlexiLingoIn one line
There are three kinds of
siand each has two fixed tenses — and aftersiyou never use a future or a conditional.
The three types
| Type | After si | Result | Meaning |
|---|---|---|---|
| 1 — real | present | future | it may happen |
| 2 — hypothetical, present | imperfect | present conditional | it is not the case now |
| 3 — hypothetical, past | pluperfect | past conditional | it did not happen and cannot now |
| Type | Example | Pronunciation |
|---|---|---|
| 1 | Si j'ai le temps, je viendrai. — if I have time, I'll come | /si ʒe lə tɑ̃ ʒə vjɛ̃.dʁe/ |
| 2 | Si j'avais le temps, je viendrais. — if I had time, I'd come | /si ʒa.vɛ lə tɑ̃ ʒə vjɛ̃.dʁɛ/ |
| 3 | Si j'avais eu le temps, je serais venu. — if I'd had time, I'd have come | /si ʒa.vɛ.z‿y lə tɑ̃ ʒə sə.ʁɛ və.ny/ |
English teaches the same three types in the same order — first, second and third conditional — and the tenses match one for one. The grammar detail is in
si-hypothese; this page is about the phrases you build with them.
Phrases
A possible hypothesis
| French | English | Pronunciation |
|---|---|---|
Si tout va bien, … | if all goes well | /si tu va bjɛ̃/ |
Au cas où… + conditional | in case | /o ka.z‿u/ |
À condition que… + subjunctive | provided that | /a kɔ̃.di.sjɔ̃ kə/ |
En cas de… + noun | in the event of | /ɑ̃ ka də/ |
Sauf si… | unless | /sof si/ |
Si jamais… | if ever, if by any chance | /si ʒa.mɛ/ |
A counterfactual hypothesis
| French | English | Pronunciation |
|---|---|---|
Si j'étais toi, … | if I were you | /si ʒe.tɛ twa/ |
À ta place, je… | in your position, I'd | /a ta plas ʒə/ |
Imagine que… + subjunctive | imagine that | /i.ma.ʒin kə/ |
Supposons que… + subjunctive | suppose that | /sy.po.zɔ̃ kə/ |
Et si… ? | what if…? | /e si/ |
Ce serait bien si… | it would be good if | /sə sə.ʁɛ bjɛ̃ si/ |
Regret
| French | Pronunciation | English |
|---|---|---|
Si j'avais su, … | /si ʒa.vɛ sy/ | if I'd known |
J'aurais dû… | /ʒo.ʁɛ dy/ | I should have |
Tu aurais pu… | /ty o.ʁɛ py/ | you could have |
Il aurait fallu… | /il o.ʁɛ fa.ly/ | we should have |
Sans toi, je n'aurais pas réussi. | /sɑ̃ twa ʒə no.ʁɛ pa ʁe.y.si/ | without you I wouldn't have made it |
Si j'avais suis the standard regret sentence and is often left unfinished — exactly like English "if I'd known…".
A hypothetical conclusion
| French | Pronunciation | English |
|---|---|---|
Ça dépendrait de… | /sa de.pɑ̃.dʁɛ də/ | it would depend on |
Ce serait plus simple. | /sə sə.ʁɛ ply sɛ̃pl/ | it would be simpler |
On pourrait… | /ɔ̃ pu.ʁɛ/ | we could |
Il vaudrait mieux… | /il vo.dʁɛ mjø/ | it would be better to |
Dans ce cas, … | /dɑ̃ sə ka/ | in that case |
Sinon, … | /si.nɔ̃/ | otherwise |
Three things that never follow si
| ❌ | ✅ |
|---|---|
Si j'aurai le temps | Si j'ai le temps |
Si j'aurais le temps | Si j'avais le temps |
Si je sois là | Si je suis là |
After
si: no future, no conditional, no subjunctive. This is one of the firmest rules in French — and French speakers themselves sometimes break it.
An apparent exception: when si means "whether", the future is possible:
Je ne sais pas si je pourrai venir.— I don't know whether I'll be able to come
Here si is not conditional but an indirect question. See question-indirecte.
English overloads "if" in exactly the same way and has the same test: if you could substitute "whether", the future is allowed.
Si j'étais toi — giving advice
The commonest use of type 2 is advice:
| French | Pronunciation | English |
|---|---|---|
Si j'étais toi, je partirais. | /si ʒe.tɛ twa ʒə paʁ.ti.ʁɛ/ | if I were you, I'd go |
À ta place, j'accepterais. | /a ta plas ʒak.sɛp.tʁɛ/ | in your position I'd accept |
Moi, je ferais autrement. | /mwa ʒə fə.ʁɛz o.tʁə.mɑ̃/ | I'd do it differently |
Si j'étais toiis politer thanTu devrais— it frames the advice as a personal view rather than an instruction.English uses the identical phrase for the identical reason — "if I were you" is softer than "you should" — so this transfers without adjustment. Note that French uses
étais, an imperfect, exactly where English uses "were".
Traps
| Trap | Explanation |
|---|---|
Never a conditional after si | Si j'avais, not j'aurais. |
Never a future after si | Si tu viens, not viendras. |
au cas où takes the conditional | Au cas où il viendrait — an exception. |
à condition que takes the subjunctive | à condition qu'il vienne. |
même si takes the indicative | même s'il est riche — not the subjunctive. |
sinon means "otherwise" | Not "if not" as two words. |
si can mean "whether" | And then the rules change. |
si — two different words with one spelling
and why only one of them has a tense rule
si does four jobs in French:
| Role | Example | Rule | Pronunciation |
|---|---|---|---|
| condition | Si tu viens, je serai content. | tenses restricted | /si ty vjɛ̃ ʒə sə.ʁe kɔ̃.tɑ̃/ |
| "whether" | Je demande s'il vient. | tenses free | /ʒə də.mɑ̃d sil vjɛ̃/ |
| contradicting a negative | — Tu ne viens pas ? — Si ! | — | /ty nə vjɛ̃ pa/ · /si/ |
| "so" | Il est si grand ! | — | /il ɛ si ɡʁɑ̃/ |
And only the first has the strict rule.
Telling them apart is easy:
If "whether" fits → indirect question, no restriction. If "if" fits → condition, the rule applies.
| Pronunciation | ||
|---|---|---|
Je ne sais pas si je viendrai. | "whether" — future allowed | /ʒə nə sɛ pa si ʒə vjɛ̃.dʁe/ |
Si je viens, je t'appelle. | "if" — future forbidden | /si ʒə vjɛ̃ ʒə ta.pɛl/ |
English has the same overlap between "if" and "whether", and the same substitution test — so that half is free.
What English does not have is the third one. Si ! contradicts a negative statement or question, and English has no word for it at all: it uses stress instead — "— You don't like it? — Yes I do." In listening, Si in that position is easy to mishear as "if", which turns the answer into nonsense. It is said loudly and with emphasis, which is the clue. See interrogation-complete.