l基本含義是“直到...才”。
I did not go home until my mother called me.
我直到我媽媽打電話給我纔回家。
Not until Father came back did we begin to have supper last night.
昨晚直到父親回來，我們纔開始吃晚飯。
not until的倒裝與強調結構，not until通常與非延續性動詞連用，強調主句所表示的狀態或情景從until所表示的'時間才發生，主句必須是否定句。
1、當Not until位於句首時,句子要倒裝。其結構爲:Not until+從句/表時間的詞+助動詞+(主句)主語+謂語
（1）Not until the teacher came in did the students stop talking.
直到老師進來學生們才停止講話。
（2）Not until next week will the sports meet be held.
直到下週纔開運動會。
2、not until的強調結構爲:It is / was not until+從句/表時間的詞+that
（1）It was not until the teacher came in that the students stopped talking.
（2）It is not until next week that the sports meet will be held.
