• The past continuous—which is also called the “past progressive”— is one of the eight basic English verb tenses. It is formed with the simple past of be (“was” or “were”) as an auxiliary followed by the ing-form of the main verb. In other words:
past continuous = be + ing-form
• The most important use of the past continuous is to describe a situation in which a shorter event is enclosed in a longer event. The past continuous is used to refer to the longer event and the simple past is used to refer to the shorter event. • for example: While Jack WAS WATCHING the movie, Jill quietly WENT OUT the back door. • for example: Harry and Sarah WERE SLEEPING upstairs when the fire STARTED. • In both the previous examples, the enclosed event is something which happened “instantaneously.” In other words it has no “duration.” This combination of simple past and past continuous can also be used when the enclosed event has duration, as long as it has less duration. • for example: While Jane WAS TALKING to her mother, Dick WROTE a letter to Harry. • In this example the implication is that Dick began his letter after Jane fell asleep and finished it before she woke up. • Sometimes, however when one event starts before a second event and then ends before the second event ends (in other words when one event “partially overlaps” another) the past continuous is used to refer to both events • for example: While Jane WAS TALKING to her mother, Dick WAS WRITING a letter to Harry. • In this example, the relationship between the events is quite vague. The only real implication is that for some period of time, both events were happening. We do not know whether one event was enclosed in another or which or whether they were just overlapping to some extent. • Sometimes the past continuous is used not in connection with another verb phrase but in connection with a reference to a point in time which is enclosed in a larger event. • for example: At the time of the theft Harry WAS VISITING his mother in the hospital.