Форма общие или задать вопрос : we have been friends since childhood, (since when) 2. the rain hasn't stopped yet. (general) 3. the film has been on for a week, (for how long) 4. he had recovered by the time i returned from my leave, (general) 5. he will have worked as a teacher for 20 years by next september, (for how long) 6. the students will have started the discussion by the time you come, (who)
2.Has the rain stopped yet?
3.How long has the film been on?
4. Had he recovered by the time I returned from my leave?
5. How long will he have worked as a teacher by next September?
6 Who will have started the discussion by the time you come?