No sooner had we started than it degan to rain.=__had we started__it began to rain.

问题描述:

No sooner had we started than it degan to rain.=__had we started__it began to rain.
为什么

began 打成degan了吧,
答案是:hardly;when
首先是一个不完全倒装,就是助动词提前到主语前,否定词提前到句首,但是实意动词还在主语后
然后是固定句型no sooner.than.=hardly.when.