
The action may have been interrupted by another event or it may have continued for some time. “The past continuous is used to describe an action in progress at a specific time in the past.

Here’s an example of the type of explanation you might find in the book, taken from Unit 9, which covers the past continuous tense: Each unit includes clear explanations of the grammar point, followed by examples and exercises to reinforce the learning. The book is divided into 145 units, each covering a specific grammar topic, such as the present perfect, passive voice, or conditionals.
