Употребить Present, Past или Future Perfect. 1. Не (to study) French before he (to enter) the university. 2. When we (to come) to the station, the train already (to leave). 3. I (to do) my homework by six o'clock tomorrow.

1. He had studied French before he entered the university. - Он изучал французский язык до того, как он поступил в университет.

2. When we came to the station, the train had already left. - Когда мы приехали на вокзал, поезд уже ушел.

3. I will have done my homework by six o'clock tomorrow. - Я сделаю свою домашнюю работу завтра к шести часам.