We have seen sentences where on means we. For example, On va au cinéma means We go to the cinema.
There is a second meaning of this word in French. You’ll use on when you do not know who did the action.
On a appelé les pompiers.
The firefighters were called.
Literal: One called the firefighters.
On a volé mon argent.
My money was stolen.
Literal: One stole my money.
On interdit de fumer dans ce restaurant.
Smoking is forbidden in this restaurant.
Literal: One is forbidden from smoking in this restaurant.
Sometimes, when talking about the past, we can use two different tenses in the same sentence, the imparfait and the passé composé. The imparfait describes the context, and the passé composé describes what happened.
Nous faisions les devoirs quand notre mère est rentrée.
We were doing our homework when our mother came home.
Il y avait beaucoup de monde dans le magasin quand elle est entrée.
There were a lot of people in the store when she came in.
If we want to use the word something followed by an adjective (for example, something interesting, something funny, something small), you use in French quelque chose de, followed by an adjective.