1. When the teacher entered the classroom, the students were talking.

Explanation:

The students were already talking at that moment in the past.

The teacher’s entry interrupted the action.

That’s why we use past continuous.

2. When I called her, she was cooking dinner.

Explanation:

Cooking was in progress when I called.

The call interrupted the action, so we use was cooking (past continuous).

3. At 8 p.m. last night, they were watching a movie.

Explanation:

“At 8 p.m. last night” is a specific time in the past.

The action was happening at that time, so we use were watching.

4. Right now, my brother is studying for his exam.

Explanation:

“Right now” shows the action is happening at this moment.

So we use present continuous → is studying.

5. While we were walking home, it was raining heavily.

Explanation:

Two actions were happening at the same time in the past.

Both actions were ongoing, so we use past continuous for both.

6. Listen! The baby is crying.

Explanation:

“Listen!” shows something is happening now.

So we use present continuous → is crying.

7. Yesterday afternoon, I was cleaning the house.

Explanation:

“Yesterday afternoon” is a time in the past, and the action was ongoing.

So we use past continuous → was cleaning.

8. Today, I am working from home.

Explanation:

“Today” shows a temporary situation, not permanent.

So we use present continuous → am working.

9. When the phone rang, they were having dinner.

Explanation:

Dinner was already happening when the phone rang.

The ringing interrupted the action, so we use past continuous.

10. Last Sunday at noon, she was preparing lunch.

Explanation:

This shows an action happening at a specific time in the past.

So we use past continuous → was preparing.

11. Look! The children are playing in the garden.

Explanation:

“Look!” shows the action is happening right now.

So we use present continuous → are playing.

12. While he was driving, he was listening to music.

Explanation:

Two actions were happening at the same time in the past.

So we use past continuous for both actions.