The second conditional (si j'avais, je ferais)

The Second Conditional

To imagine a hypothetical situation in the present or future, use the second conditional. In English, we say "If I were on Mars, I would wear a spacesuit."

In French, pair si (if) with the imparfait (imperfect tense) for the condition, and use the conditionnel (conditional tense) for the result:

Si + [Imparfait] ➔ [Conditionnel]

If the gravity were less strong, the astronaut would float.
Si la gravité était moins forte, l'astronaute flotterait.
If I were on Mars, I would wear the suit for the oxygen.
Si j'étais sur Mars, je porterais la combinaison pour l'oxygène.
If we had a base in the galaxy, we would live there.
Si nous avions une base dans la galaxie, nous y habiterions.

Elision with "Si"

The word si drops its i and uses an apostrophe before il or ils (s'il, s'ils). It does not change before elle or elles (si elle, si elles).

If there were no gravity, everything would float.
S'il n'y avait pas de gravité, tout flotterait.
If they left the solar system, they would explore a new galaxy.
S'ils quittaient le système solaire, ils exploreraient une nouvelle galaxie.