有關英文句子既問題想問問大家

Past tenses

你的句子說的兩件事，Sam gave up smoking (戒煙)yesterday發生在he smoked(吸煙) for twenty years 之後，所以寫成一句時，前者用simple past tense後者寫past perfect tense便可。後者寫past perfect continuous tense是不恰當的。
"When Sam gave up smoking yesterday, he had been smoking for twenty years."可改正為
"When Sam gave up smoking yesterday, he had smoked for twenty years."
另外也可寫為:
Sam gave up smoking yesterday after smoking for twenty years.


2014-03-01 21:28:14 補充：
Sam smoked for twenty years until he gave up smoking yesterday.

2014-03-01 21:37:31 補充：
如果事情在yesterday前開始發生至yesterday仍繼續進行，才可用past perfect continuous tense，例如:
When Sam started to smoke Marlboro yesterday, he had been smoking for twenty years.

使用 When 並不合適。
因為兩個分句無"當"既意思。

可能你中文想話
當 Sam 放棄食煙果刻, 佢已經食左 20 年。

但英文黎講, 應該要甘寫
Sam had smoked for twenty years. He gave up smoking yesterday.

有一個錯既問題.


呢個句子可以話有2 parts :

1) Sam gave up smoking yesterday
2) He had been smoking for twenty years


你個句子用左, "when" Sam gave up smoking yesterday, he had been smoking for twenty years, 個when 用得唔好.

如果我直接translate到中文既話,你個句子既意思就會變左:

當sam放棄食煙既時候, 佢以前食左20年煙.

個logic 完成不成立, 所以要整走個when 佢:

正確既會係 Sam gave up smoking yesterday. he had been smoking for twenty years.

2014-03-01 19:02:24 補充：
你都可以用";" 去分離2句句子,

如:

Sam gave up smoking yesterday; he had been smoking for twenty years.

幾時用";" ? 當你有2個independent clause 既時候可以用, independent clause 指句句子可以自己企出黎, 唔會無左前面果句, 後面就唔會make sense, vice versa.