When

Hi, Ahmed,

@Ahmed.A.A posted:

Hi, Is the following sentence OK?

''When he was drawing a picture, I was watching a movie.''

I think it is OK if ''when'' is used instead of ''while'' to express two actions happening at the same time in the past.

Yes, it is. In 'Advanced Grammar In Use', you can find the following example (page 8):

- When I was learning / learned to drive, I was living with my parents.

Thanks a lot Ahmed

@Ahmed.A.A posted:

''When he was drawing a picture, I was watching a movie.''

I think it is OK if ''when'' is used instead of ''while'' to express two actions happening at the same time in the past.

Hi, Ahmed.A.A—I agree with Ahmed_btm that both "when" and "while" can be used there. It should be noted that in such sentences the progressive is used in the "when"-clause. If the past simple were used, only "while" would work:

(1a) While he was drawing a picture, I was watching a movie.
(1b) When he was drawing a picture, I was watching a movie.

(2a) While he drew a picture, I watched a movie.
(2b) When he drew a picture, I watched a movie.

Sentence (2b) has a totally different meaning from that of the first three examples. It is talking either about two activities beginning at the same time or about their habitual cooccurrence: "Whenever he did this, I did that."

Thanks David, but concerning Sentence 2a, is it possible to use past simple after ''while'' instead of past continuous? Are they always interchangeable?