- we were doing smth at a certain period of time in the past (действие в прошлом в определенный период времени): At 9 in the evening I was having a shower.
- to say that smth happened in the middle of smth else (usually we use past simple & past continuous together) - (часто, то, чем вы как раз занимались в определённое время в прошлом, перебивается другим действием): Ben phoned when we were cooking. It was raining when she went out.
+ was/were + Ving: I was walking that moment. /You were sleeping when we came
- wasn’t/weren’t + Ving: He wasn’t reading at 5. /They weren’t riding at noon
? Was/Were + Ving: Was she smiling that moment? /Were you dancing? /Was he waiting for you?
Markers: that momet, at 5 o’clock.