When to use the passé composé? - Quand se servir du passé composé ?
It is tricky to speak in the past in French because you have to choose between the passé composé and the imparfait.
Use the passé composé when an action happened only once, or was short and sudden, specific, actions that were completed at some point in the past, and when you are talking about precise information.
Look at this passage
Suddenly, it started raining. It rained for two hours. I gathered my stuff in three minutes. Isabelle and I laughed the whole time.
Soudain, il a commencé à pleuvoir. Il a plu pendant deux heures. J’ai ramassé mes affaires en trois minutes. Isabelle et moi avons ri tout le temps.
In a nutshell, if you’re asking the question
What happened?, use the passé composé