你說的的是 had been doing 和 had done 結(jié)構(gòu)嗎?
過去完成進(jìn)行時(shí)(had been doing )表示過去某一時(shí)刻之前開始的動(dòng)作或狀態(tài)一直延續(xù)到過去某一時(shí)刻.例如：
It had been raining cats and dogs for over a week and the downpour had caused landslides in many places.
過去完成時(shí)(had done)表示過去某時(shí)間前已經(jīng)發(fā)生的動(dòng)作或情況,這個(gè)過去的時(shí)間可以用by,before等介詞短語或一個(gè)時(shí)間狀語從句來表示；或者表示一個(gè)動(dòng)作在另一個(gè)過去動(dòng)作之前已經(jīng)完成.
1)We had just had our breakfast when Tom came in.
2)By the end of last year they had turned out 5, 000 bicycles.
至于哪個(gè)延續(xù)時(shí)間長(zhǎng)?只有前者表動(dòng)作的持續(xù),后者表動(dòng)作的完成.