Use Past Simple or Past Perfect :
1. When I (get) to the cinima the film (start).
2. The students (do) the exercise very well after the teacher (show) them how to do.
3. The little boy (tell) a lie five minutes after he (promise) to tell the truth.
1. When I got to the cinima the film had started.2. The students did the exercise very well after the teacher had showed them how to do.3. The little boy told a lie five minutes after he had promised to tell the truth.