“认识并熟悉某人/物”，是延续性动词。

I know him so well that I can recognise his steps.

youdao

当他接到信后，他会告诉我们的。（非延续性动词）

When he received the letter, he'll tell us.

youdao

（make为延续性动词）当她在打电话时，我正在写信。

When /While /As she was making a phone call, I was writing a letter.

youdao

（make为延续性动词）当她在打电话时，我正在写信。

When /While /As she was making a phone call, I was writing a letter.

youdao