He had waiteduntil she had finished her work.

He had waiteduntil she finished her work.

以上二個句子有細微差別。假定she完成工作的時間為五點十分。第一句表示他等到五點十五分左右，見到了她，等待的動作結束。

第二句則表示他等到她五點十分干完活，結束等待。

第一句之所以用二個過去完成時，是由于說話人心目中關注的時間是五點十五分他見到她這個時間，而等待wait和finish這二個動作都是在五點十五分之前發生的。所以主從句都用過去完成時。但事實上，until從句用一般體和完成體的時間差異非常小，一般讓人們忽視，因此一般在until從句用完成體較少。有些語法書甚至覺得用完成體和一般體意義相同。這是忽視細微的時間差別。

以下四個句子意義相差不大，或者說可以忽視他們之間的差別：



He had waiteduntil she had finished her work.

He had waiteduntil she finished her work.

He waiteduntil she had finished her work.

He waiteduntil she finished her work.