until用法

until 的用法 一, 介词 until 作介词的 until 的英文解释是 up to a specified time (直到某一时刻)或 up to the time of a specified event (直到发生某事).但注意观察下列句子,我们还可留意到 until 在具体运用中 的细微之处. 1. 用于肯定句中: 1) It may last until Friday. 这可能要延续到星期五. 2) He will be working until 5 o'clock. 他将一直工作到五点钟. 3) She was a bank clerk until the war, when she trained as a nurse. 她战前是个银行职员, 战时 受训当了护士. 不难看出 until 用于肯定句中,表示句子的动作一直持续到 until 短语所表示的时间为止, 即表示动作的终点.一般可译为"直到……时(为止)"或"在……以前" .在这种用法中, 句子的谓语动词必须是持续动词(非瞬间动词),如 live, wait , last, love, like, stay, work, continue 等. 二, 连词 until 以同样的方式分析作连词的 until 的用法.作连词用的 until 的英文释义是 up to the time when(直到……时为止). 1. 用于肯定句中: 1) Heat can be conducted from a hot body to a cooler one until both are at the same temperature. 热可以从一个热的物体传到一个较冷的物体,直到两者温度相同为止. 2) Continue in this direction until you see a sign. 一直朝着这个方向走就会看见指示牌了. 3) He ran until he was breathless. 他一直跑到气喘吁吁才停下. 不难看出,作连词的 until 用于肯定句中,表示主句的动作一直持续到从句动作发生或状 态出现时为止.一般可译为"……直到……为止" .在这种用法中,主句的谓语动词必须是 持续动词(非瞬间动词),如 live, wait , last, love, like, stay, work, continue 等. 2. 用于否定句中: 1) I hadn't realized she was foreign until she spoke. 她不说话我还一直不知道她是个外国人. 2) I won't stop shouting until you let me go. 你不放我,我就一直喊叫. 3) Among the great mathematicians there are about as many who showed mathematical talents in childhood as there are those who showed none at all until they are older. 在伟大的数学家中, 童年就显露数学才华的人和直到相当年龄才显露才华的人差不多一样多. 不难看出, 作连词的 until 用于否定句中, 从句先发生, 主句再发生. 一般可译为 "直到…… 才" .

attention：一,until与by的区别 1. by表示在某特定的时间之前或不迟于某特定的时间,意为"最迟在;不迟于"或"在……之 前"等.如: ①I will finish my task by nine.我将在九点钟前完成任务. ②The plane takes off at 10:00, so you must try to be at the airport by 9:30. 飞机在十点钟起飞,所以你必须在九点半赶到机场. 2. until用在肯定句,谓语动词通常是延续性动词,如stand, stay, talk, wait等,表示主 句动作终止的时间.如: ③I waited until he came back.我一直等到他回来. ④The war lasted until 1945.战争持续到1945年. 如果用在否定句,谓语动词通常是瞬间性动词,如open, start, leave, arrive, finish, stop等,强调主句动作开始的时间.如: ⑤I didn't leave the boy until his mother turned up.直到这孩子的母亲来,我才离 开. ⑥The 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与before的区别 1.可直接换用的情况:在until能使用的句型中,即主句含有否定式终止性谓语动词或肯定式 延续性动词,可与before直接替换,意义差别不大.如: ①The students won't go home until / before they finish their homework.学生们 要先完成作业才能回家. ②The woman worked in the factory until/before 1990. 1990年以前这妇女在这家工 厂上班. 2.不可换用的情况:当主句含有肯定式终止性谓语动词时,只能用before不能用until,且 before常意为"没来得及……"或"……才……"等.如: ③Einstein almost knocked me down before he saw me.爱因斯坦差不多将我撞倒才看 见了我. ④He had measured me before I could get in a word.我还没来得及插话,他就把我的 尺寸量好了.

引用他人，绝非原创，只是资源***享 O(∩_∩)O~~