比較until和till

此兩個連詞意義相同。肯定形式表示的意思是"做某事直至某時"，動詞必須是延續(xù)性的。否定形式表達(dá)的意思是"直至某時才做某事"。動詞爲(wèi)延續(xù)性或非延續(xù)性都可　以。 正確使用這兩個連詞的關(guān)鍵之一就在於判斷句中的動詞該用肯定式還是否定式。

肯定句： I slept until midnight. 我一直睡到半夜時醒了。 Wait till I call you.等著我叫你。 （在肯定句中可用before代替 Let's get in the wheat before the sun sets.）

否定句： She didn't arrive until 6 o'clock. 她直到6點(diǎn)才到。 Don't get off the bus until it has stopped. 公共汽車停穩(wěn)後再下車。 I didn't manage to do it until you had explained how. 直到你教我後，我才會做。

1)Until可用於句首，而till通常不用於句首。 Until you told me, I had heard nothing of what happened. 直到你告訴我以前，出了什麼事我一點(diǎn)也不知道。 2)Until when 疑問句中，until要放在句首。 ---Until when are you staying?　你呆到什麼時候？ --- Until next Monday.　呆到下周一?！?/p>

注意：否定句可用另外兩種句式表示。 (1）Not until …在句首，主句用倒裝。 Not until the early years of the 19th century did man know what heat is. 直到19 世紀(jì)初，人類才知道熱能是什麼。 Not until I began to work did I realize how much time I had wasted. 直到我開始工作，我才認(rèn)識到了我已蹉跎了幾多嵗月。 (2)　It is not until… that…