when and while...

Question: How do I choose between when and while?

Grammar: Adverbs (time expressions)

When is used for shorter actions, and while is used for longer actions.

When is usually used with simple tenses, and while with progressive tenses.

For example, let’s look at two actions, one short and one long:
Short action – Fall down (it only takes a second to fall down)Long action – Ride a bike (bike rides can last a long time)Because one is long and one is short, these two actions can’t happen at the same time. The short action interrupts the long action:

I was riding my bike when I fell down.I fell down while I was riding my bike.Let’s consider two more actions:

Reading a bookTelephone ringingIt is clear that the telephone ringing is the shorter action, it only takes a few seconds:

I was reading a book when the telephone rang.The telephone rang while I was reading a book

 while we use when we speak of two events at the same time is nesesario utiizar time spent or progressive actions of one of the other can go on past simple


Both are adverbs, and both are used to talk about a 'background' event or situation that happens at the same time as something else. Here are a couple of examples:

It was raining when I arrived.

I usually eat my dinner while he tells me about his day.

If both the 'background' event and the 'main' event are long we usually use while:

I read my book while she slept.

But if both if the events are short we can only use when:

He smiled when he arrived.

Also, if we are talking about periods of life we only use when:

When I was a child I played with dolls a lot.