1 Use when, before or after, the past perfect and the past simple to join the sentences, as in the example. 1 The scientist made an announcement. He completed his research.> When the scientist (had) completed his research, he made an announcement./The scientist made an announcement after he had completed his research. 2 She got a degree in Engineering. She studied for four years. 3 He worked as a sales assistant. He got a new job as a car salesman. 4 Ann and David were engaged for five months. They got married. 5 Mr. Harris was sick for many weeks. He went to hospital.