Can I use “when” to start a sentence with the past progressive?

Question

My class is working on the past progressive and the simple past, and I was wondering if I can use when instead of while for the following sentence

While I was eating, the bell rang.

When I was eating, the bell rang.

Thank you

Answer 1

An adverbial clause beginning with when (or indeed with any subordinating conjunction), can be used grammatically in any tense. (BTW, "past progressive" is not a tense; past is a tense, and progressive is a construction).

As for the difference between when and while, the first is general and non-specific, but while implies an event with duration that contains a point in time (While he slept/was asleep/was sleeping, the phone rang) or that overlaps some other duration (While he read/was reading, she was writing).

Answer 2

They mean different things.

• While = during the time I was doing something.

• When = over the entire period of time. So:

  While I was working, someone called. When I was working at the mall, I was never at home. When Bill was running, he lost a lot of weight.

Answer 3

"while" does indeed mean "during that time", but it could be any part of that time, even a short part (we presume the bell was not ringing the ENTIRE time you were eating—although "while" does not exclude that possibility, if that were the case, we would say "the bell kept ringing all the time [while] I was eating").

But "when" is often used to mean "at a specific time", rather than over the entire period of time. Thus we would more likely say "the bell rang when I started eating" or "the bell rang {when/as} I finished eating".

So it is not wrong to use "when", but "while" fits better with the ongoing nature of past progressive "was eating".