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Can I interchange while and when in the following sentences?

1- He waited while/when I combed my hair.

2- He was waiting while/when I was combing my hair.
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"while" is a better choice in both those sentences, at least in normal circumstances.

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For posts on "when" and "while", see the links below. One or more of them may contain something you'll find useful.

When or while
The Past Simple/Continuous with a while/when clause
Time relationships
When / while he slept / was sleeping

CJ