Answer:
The German imperfect tense is used:
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.
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.
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.
Note that if you want to talk about an event or action that took place and was completed in the past, you normally use the perfect tense in German conversation. The imperfect tense is normally used in written German.
Was hast du heute gemacht? -> What have you done today?
When 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.
Sie war seit ihrer Heirat als Lehrerin beschäftigt.-> She had been working as a teacher since her marriage.
Explanation: