The conjunction "si" is used to introduce a condition that must be met for a consequence to occur. In French, there are three main types of conditional sentences with "si," each corresponding to a different hypothetical situation.

Type 1 Condition: Possible Reality in the Present or Future

This type of condition expresses a situation that can actually happen in the present or future if the condition is met.

  • Si tu étudies, tu peux réussir ton examen. (If you study, you can pass your exam.)
  • Si nous partons maintenant, nous arriverons à l'heure. (If we leave now, we will arrive on time.)
  • Si elle le demande, je lui prêterai mon livre. (If she asks, I will lend her my book.)

Type 2 Condition: Hypothetical Situation

This form expresses a hypothetical situation, often unreal in the present, but imaginable under certain conditions.

  • Si j'avais un million d'euros, j'achèterais une maison. (If I had a million euros, I would buy a house.)
  • Si tu savais voler, où irais-tu ? (If you could fly, where would you go?)
  • Si elle était ici, elle serait heureuse. (If she were here, she would be happy.)

Type 3 Condition: Past and Unachievable Situation

Expresses regret or the consequence of an action that did not happen in the past.

  • Si j'avais étudié, j'aurais réussi mon examen. (If I had studied, I would have passed my exam.)
  • Si nous avions pris le train plus tôt, nous n'aurions pas manqué le rendez-vous. (If we had taken the earlier train, we wouldn't have missed the appointment.)
  • Si elle avait écouté, elle n'aurait pas fait cette erreur. (If she had listened, she wouldn't have made that mistake.)