The document discusses the use of the past continuous tense in English. It is used to describe an action or situation that was ongoing or in progress at a specific time in the past. Some key points made include: - The past continuous uses "was/were + verb+ing" and shows that an action started in the past and may or may not have finished. - It is used to ask what someone was doing at a specific time (e.g. "What were you doing yesterday?"). - Certain verbs like know, want, believe are not usually used in the past continuous. - The past continuous can be used with the past simple to show something happened during or after another ongoing action.