Imparfait vs. Passé composé

Bonjour Wyn Ron !

Aaah the eternal question ;)
Knowing when to use L'Imparfait versus Le Passé Composé can indeed be complicated for learners, so here are some guidelines:

-> Imparfait is used to express:
- a habit in the past = used to
- a continuous action in the past = was doing
- to describe a past state or situation = it was
- after "si" in hypothetical statements = if I had

-> Passé Composé is used to express:
- a past action with a clear beginning and end in the past = did
- a brief action in the past

Here are links to our related lessons for more examples :
Expressing continuing action in L'Imparfait (imperfect tense)">Expressing continuing action in L'Imparfait (imperfect tense)">Expressing continuing action in L'Imparfait (imperfect tense)">Expressing continuing action in L'Imparfait (imperfect tense)
Expressing habits or repeated actions in L'Imparfait (imperfect tense)">Expressing habits or repeated actions in L'Imparfait (imperfect tense)">Expressing habits or repeated actions in L'Imparfait (imperfect tense)">Expressing habits or repeated actions in L'Imparfait (imperfect tense)
Describing and expressing opinions in L'Imparfait (imperfect tense)">Describing and expressing opinions in L'Imparfait (imperfect tense)">Describing and expressing opinions in L'Imparfait (imperfect tense)">Describing and expressing opinions in L'Imparfait (imperfect tense)
Using L'Imparfait in hypothetical clauses introduced by si (if) + Le Conditionnel Présent
and
Using Le Passé Composé on its own or with L'Imparfait">Using Le Passé Composé on its own or with L'Imparfait">Using Le Passé Composé on its own or with L'Imparfait">Using Le Passé Composé on its own or with L'Imparfait

I hope that's helpful!
À bientôt !

Bonjour Aurelie, merci de votre aide. For example, I want to say the airplane was on time, when I am in conversation with a friend whom asked me "how was your vacation?". Do I say? Le vol était à l'heure (this described the situation) or Le vol a été à l'heure (this action had a beginning and an end in the past) Wyn

Bonjour Wyn Ron ! In that case, it's a description, so you will use L'Imparfait :) Bonne journée !