The past progressive (past continuous) is "was visiting." (were visiting) The past perfect progressive is "had been visiting."
Past progressive tense.
The past progressive tense has two forms: simple past progressive (e.g., "I was reading") and past perfect progressive (e.g., "I had been reading"). Both forms indicate an ongoing action in the past.
The past progressive tense of "study" is "was/were studying."
The past progressive of "think" is "was thinking" or "were thinking." The past perfect of "see" is "had seen."
the form of the past tense are past progressive,past perfect progressive,past perfect simple.
Present progressive, past progressive, and future progressive
Was/were starting is the past progressive tense of start.
Past simple - I laughed. Past progressive - I was laughing.
The past perfect progressive tense of "to investigate" is "had been investigating."
The past progressive of "stop" is "was stopping" or "were stopping" depending on the subject.
Use past progressive tense to indicate an action that was ongoing in the past. Use past perfect progressive tense to show a continuous action that started before a certain point in the past and continued up to that point.