Hypothesis and condition with si

Three systems: si + present / imparfait / pluperfect.

⚡Key points

1. Real→Si + present → present / future

2. Hypothetical→Si + imparfait → present conditional

3. Unreal in the past→Si + pluperfect → past conditional

After si — NEVER future/conditional→only present / imparfait / pluperfect

System 1: real condition

If the condition is real or likely: si + present, and the main clause uses the present, future simple or imperative. This concerns the present or the future.

Si + present → present / future / imperative

General truth / habit

Si on chauffe l’eau, elle bout. (If you heat water, it boils.)

Likely future

S’il fait beau demain, j’irai à la plage. (If it’s sunny tomorrow, I’ll go to the beach.)

Advice / order

Si tu es fatigué, repose-toi. (If you’re tired, rest.)

Systems 2 and 3: hypothesis and unreality

If the condition is unlikely or unreal in the present: si + imparfait → present conditional. If it is about the past, now unchangeable: si + pluperfect → past conditional (regret).

The three systems

1. Real	Si tu veux, on sort.	present → present
1. Future	S’il pleut, je resterai.	present → future
2. Hypothesis	Si j’avais de l’argent, je voyagerais.	imparfait → present cond.
3. Past	Si j’avais su, je serais venu.	pluperfect → past cond.

💡⚠️ After si — never future or conditional

After si (the condition) you use only the present, imparfait or pluperfect. The future and conditional go in the main clause, not after si. You cannot say “si je serais”, “si j’aurai”.

Si j’ai le temps, je viendrai. (✓ present after si)

Si j’avais le temps, je viendrais. (✓ imparfait after si)

Dialogue: holiday plans

ClaraSi on a assez d’argent, on ira en Italie cet été.

LucasEt si on n’en avait pas assez, on resterait en France.

ClaraL’an dernier, si on avait réservé plus tôt, on aurait payé moins cher.

LucasC’est vrai. Cette fois, si tu veux, je réserve dès demain.

Clara: If we have enough money, we’ll go to Italy this summer. | Lucas: And if we didn’t have enough, we’d stay in France. | Clara: Last year, if we had booked earlier, we would have paid less. | Lucas: True. This time, if you want, I’ll book tomorrow.