下面是小編整理的一些關(guān)于until的用法詳解，歡迎大家閱讀!

　　一、until與by的區(qū)別

　　1. by表示在某特定的時間之前或不遲于某特定的時間,意為"最遲在;不遲于"或"在……之前"等。如:

　?、買 will finish my task by nine.我將在九點鐘前完成任務(wù)。

　　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(xù)性動詞,如stand, stay, talk, wait等,表示主句動作終止的時間。如:

　?、跧 waited until he came back.我一直等到他回來。

　?、躎he war lasted until 1945.戰(zhàn)爭持續(xù)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(diào)主句動作開始的時間。如:

　?、軮 didn't leave the boy until his mother turned up.直到這孩子的母親來,我才離開。

　?、轙he noise of the street didn't stop until it was midnight.街上的噪音直到半夜才停止。

　　二、until與before的區(qū)別

　　1.可直接換用的情況:在until能使用的句型中,即主句含有否定式終止性謂語動詞或肯定式延續(xù)性動詞,可與before直接替換,意義差別不大。如:

　?、賂he students won't go home until / before they finish their homework.學(xué)生們要先完成作業(yè)才能回家。

　?、赥he woman worked in the factory until/before 1990. 1990年以前這婦女在這家工廠上班。

　　2.不可換用的情況:當(dāng)主句含有肯定式終止性謂語動詞時,只能用before不能用until,且before常意為"沒來得及……"或"……才……"等。如:

　　③Einstein almost knocked me down before he saw me.愛因斯坦差不多將我撞倒才看見了我。

　?、蹾e had measured me before I could get in a word.我還沒來得及插話,他就把我的尺寸量好了。

　　三、not until的倒裝與強調(diào)結(jié)構(gòu)

　　1.當(dāng)Not until位于句首時,句子要倒裝。其結(jié)構(gòu)為:Not until+從句/表時間的詞+助動詞+(主句)主語+謂語+...。如:

　?、貼ot until the teacher came in did the students stop talking.直到老師進來學(xué)生們才停止講話。

　?、贜ot until next week will the sports meet be held.直到下周才開運動會。

　　2. not until的強調(diào)結(jié)構(gòu)為:It is / was not until+從句/表時間的詞+that+...。上面兩句改為強調(diào)句為:

　?、跧t was not until the teacher came in that the students stopped talking.

　　④It is not until next week that the sports meet will be held.