Now that you know how to form the imparfait, the real question is when to reach for it instead of the passé composé. The short answer: whenever you're painting a picture of how things were, rather than reporting what happened.
1. Describing the past
| Il faisait beau. | It was nice out. |
| Elle avait les cheveux longs. | She had long hair. |
| La maison était grande. | The house was big. |
2. Habitual actions: "used to"
| Je jouais au foot tous les samedis. | I used to play soccer every Saturday. |
| Nous allions à la plage chaque été. | We used to go to the beach every summer. |
3. Ongoing background action
The imparfait often sets the scene for something else that happens, usually a sudden event in the passé composé.
| Je dormais quand le téléphone a sonné. | I was sleeping when the phone rang. |
4. Mental and emotional states
| Je pensais que tu venais. | I thought you were coming. |
| Elle voulait partir tôt. | She wanted to leave early. |
| Il savait que c'était risqué. | He knew it was risky. |
5. Quick reference
| description | people, places, weather, age, time in the past |
| habit | "used to," repeated actions |
| background | what was going on when something else happened |
| mental state | thinking, wanting, knowing, feeling |