The Future Perfect and the Future Perfect Continuous

The time phrases begin with in or on. When and by the time are followed by a verb. This verb is in the present, simple, not the future. We can also use the future perfect and future perfect continuous to say what we imagine might or might not have happened. They won't have arrived yet. They only left 20 minutes ago. Sam didn't come home last night. He'll have been working all night to finish his report. On sunday, he'll have been travelling for three weeks. By the summer, i'll have finished all by exams. The film won't have started yet.