1. hardly/scarcely…when/before, no sooner…than 和as soon as都可以表示"一…就…"的意思，例：
I had hardly got home when it began to rain.
I had no sooner got home than it began to rain.
As soon as I got home, it began to rain.
2. 注意：如果hardly, scarcely 或no sooner置於句首，句子必須用倒裝結構，例：
Hardly / Scarcely had I got home when it began to rain.
No sooner had I got home than it began to rain.