[文法Q&A]
Q: by和until有什麼區別?
A:
1. by表示在某特定的時間之前或不遲於某特定的時間，意為“最遲在;不遲於”或“在……之前”等。如：
①I will finish my task by nine. 我將在九點鐘前完成任務。
②The plane takes off at 10:00, so you must try to be at the airport by 9:30. 飛機在十點鐘起飛，所以你必須在九點半趕到機場。
2. until用在肯定句，謂語動詞通常是延續性動詞，如stand, stay, talk, wait等，表示主句動作終止的時間。如:
③I waited until he came back. 我一直等到他回來。
④The war lasted until 1945. 戰爭持續到1945年。
如果用在否定句，謂語動詞通常是瞬間性動詞，如open, start, leave, arrive, finish, stop等，強調主句動作開始的時間。如:
⑤I didn't leave the boy until his mother turned up.直到這孩子的母親來，我才離開。
⑥The noise of the street didn't stop until it was midnight. 街上的噪音直到半夜才停止。
Sources:
http://ask.koolearn.com/topic/show/308996.page
http://www.pearsonlongman.com/ae/azar/grammar_ex/message_board/archive/articles/00016.htm
http://www.engvid.com/by-until/
Search