The imperfect tense is normally used in written German.
It is used to talk about the past especially in descriptions, and to say what used to happen.
eg, It was sunny at the weekend; I used to walk to school.
1) to describe actions in the past which the speaker feels have no link with the present
Er kam zu spät, um teilnehmen zu können. | He arrived too late to take part. |
2) to describe what things were like and how people felt in the past
Ich war ganz traurig, als sie wegging. | I was very sad when she left. |
Damals gab es ein großes Problem mit Drogen. | There was a big problem with drugs at that time. |
3) to say what used to happen or what you used to do regularly in the past
Wir machten jeden Tag einen Spaziergang. | We used to go for a walk every day. |
Samstags spielte ich Tennis. | I used to play tennis on Saturdays. |
4) using seit or seitdem
to describe something that had happened or had been true at a point in the past.
the imperfect is used in German, where in English a verb form with had is used (had done/had been doing)
Sie machte es seit Jahren. | She had been doing it for years. |
Sie war seit ihrer Heirat als Lehrerin beschäftigt. | She had been working as a teacher since her marriage. |