on, the French way to be impersonal
CEFR B1 · part 2
edumaterial's parts within the level. The European framework does not subdivide them.
After a preposition, the infinitiveUsing en + present participle for simultaneity, and an infinitive after any preposition.After si, never the futureBuilding all three conditional types, and never putting a future or conditional after si.Spoken French and written FrenchRecognising what is normal in speech but not in writing, and switching register without…celui, celle, ceux, cellesReplacing the noun without repeating it, and always following the pronoun with de, qui…en France, au Portugal, à ParisChoosing the preposition by the gender and number of the place, for going and for coming.le mien, le tien, le sienAnswering «whose is it?» without repeating the noun, with the article in front and…The rule, in three lines
on is a third-person singular subject meaning «people», «someone» or, in speech, «we». It is the natural French way of being impersonal.
The usual slip. Overusing the passive, because English builds passives far more readily than French.
Why it catches you out. English has neither «se» nor on: it reaches for a passive («French is spoken here») or for «one», which sounds stiff. So you write passives where French would use on, and they read as heavy.