The family … dinner when we knocked at the door.

Analyze the question

The sentence is "The family __ dinner when we knocked at the door." It tests tense agreement and the use of the past continuous tense.

Explain the concept

The past continuous tense (was/were + verb-ing) describes an action that was already in progress in the past when another, shorter action interrupted it.

• Longer, ongoing action → past continuous (was having)
• Shorter, interrupting action → simple past (knocked)

Pattern: past continuous + when + simple past

Step-by-step solution

1. The clause "when we knocked at the door" is in the simple past, so the main action must also be in the past.
2. The family's dinner was already going on when the knock happened, so we need the past continuous.
3. "The family" is a collective noun treated as a single unit, so it takes was, not "were".

Checking the options:

• A. is having: present continuous, so the tense clashes with "knocked". ✗
• B. was having: past continuous, the correct choice for an action in progress. ✓
• C. had: simple past, which would suggest they ate and finished, or just "possessed" dinner. It does not show an action in progress. ✗
• D. has had: present perfect, which doesn't fit a past time clause. ✗

Answer: B. was having

Exam tip

When you see "when + simple past" in a sentence, look for the past continuous (was/were + -ing) in the other clause. It shows what was going on in the background when the interruption happened.