句型
had + 過去分詞
例句：
- Mr. Chen had studied English before he moved to San Francisco. (陳先生搬到舊金山之前已學了英文)
- Had Mr. Chen studied English before he moved to San Francisco? (陳先生搬到舊金山之前已學了英文嗎？)
- Mr. Chen had not studied English before he moved to San Francisco. (陳先生搬到舊金山之前沒有學英文)
用法之一：發生在過去某個動作或某一特定時間之前的動作
過去完成式係用來表示發生在過去某個動作之前的動作；它亦可用來表示發生在過去某一特定時間之前的動作。換言之，在過去兩個先後發生的動作中，發生在前的動作用過去完成式，而發生在後的動作用過去簡單式。
例句：
- I had never seen such a beautiful beach before I went to Pescadores. (在我去澎湖之前，我從未看過這麼美麗的海灘)
- I did not have any money because I had lost my wallet. (我身無分文，因為我遺失了錢包)
- Sam knew Bangkok so well because he had visited the city several times. (山姆對曼谷瞭若指掌，因為他已去過該市好幾趟)
- Had Cindy ever studied Thai before she moved to Thailand? (辛蒂搬到泰國之前有學過泰語嗎？)
- Patricia had never been to a concert before last night. (在昨晚之前，派翠西亞從未聽過演唱會)
- We were not able to get a hotel room because we had not booked in advance. (我們沒有飯店房間可住，因為我們事先沒有預訂)
- A: Had you ever visited the U.K. before your trip in 2011? (在 2011 年的英國行之前，你有去過英國嗎？)
B: Yes, I had been to the U.K. once before. (有，我之前去過一次)
用法之二：從過去持續到過去另一個動作的時間 (非進行式動詞)
對於非進行式動詞及若干混合動詞的非進行式用法，我們使用過去完成式來表示某事發生在過去且一直持續到過去的另一個動作。
例句：
- We had had that car for ten years before it broke down. (那部車在發生故障之前，我們已經開了十年)
- By the time Allen finished his studies, he had been in New York for over eight years. (到了艾倫完成他的學業，他已在紐約待了超過八年)
- They felt bad about selling the house because they had owned it for more than forty years. (他們對於賣掉那間房子感到難過，因為那房子他們已住了超過四十年)
雖然上述的過去完成式用法通常僅限於非進行式動詞及若干混合動詞的非進行式用法，但 “live”、”work,”、”teach” 和 “study” 等動詞雖不是非進行式動詞，但有時也這樣用。
重點提示：過去完成式與特定時間
與現在完成式不同的是，雖然過去完成式亦可與時間副詞或副詞片語連用，但這通常不必要。
例句：
- She had visited her American relatives once in 2008 before she moved in with them in 2012. (她在 2012 年搬去和她的美國親戚一塊住之前，僅在 2008 年拜訪過他們一次)
此外
如果過去完成式的動作是發生在某一特定時間，那麼當句中使用了 “before” 或 “after” 時，我們可以使用過去簡單式來代替過去完成式，因為 “before” 和 “after” 已告訴我們那個動作先發生，所以使不使用過去完成式都可以。因此，下面兩句都對。
例句：
- She had visited her American relatives once in 2008 before she moved in with them in 2012.
- She visited her American relatives once in 2008 before she moved in with them in 2012.
然而
如果過去完成式不是指發生在某一特定時間的動作，那麼就一定要使用過去完成式。以下面兩句為例，過去完成式是指缺乏某種經驗而非發生在某一特定時間的動作，因此不可使用過去簡單式。
例句：
- Katie had never seen a polar bear before she moved to Canada. (凱蒂在搬到加拿大之前從未看過北極熊) (正)
- Katie never saw a polar bear before she moved to Canada. (誤)
副詞的位置
always, usually, only, never, ever, still, just 等副詞通常位在助動詞 had 的後面，即位在 had 和過去分詞之間。
例句：
- Daniel had previously studied Japanese before he moved to Japan. (丹尼爾在搬到日本之前已先學了日語)
- Had Daniel previously studied Japanese before he moved to Japan? (丹尼爾在搬到日本之前已先學了日語嗎？)
主動態/被動態
例句：
- Tim had repaired many cars before he received his mechanic’s license. (提姆在取得機工執照之前已修理過許多車輛) － 主動態
- Many cars had been repaired by Tim before he received his mechanic’s license. (在提姆取得機工執照之前，已有許多車輛被他修理過) － 被動態