not...until的基本含义是直到...才，在...以前不。not…until通常与非延续性动词连用，当其位于句首时，句子要倒装。其倒装句结构为:Not until+从句/表时间的词+助动词+(主句)主语+谓语。
not...until的倒装句结构
倒装句结构：Not until+从句+倒转的主句（主倒从不倒）
not until 引起的时间状语置于句首时，句子的主谓应部分倒装。由 not until 引导的时间状语从句位于句首时，主句应部分倒装，从句语序不变。
例句：
Not until Father came back did we begin to h***e supper last night.
昨晚直到父亲回来,我们才开始吃晚饭。
Not until the teacher came in did the students stop talking.
直到老师进来学生们才停止讲话。
not...until的强调句结构
强调句结构：It is / was not until+从句/表时间的词+that+主句
1、not until 后边一般是时间点，如：
It was not until midnight that it stopped raining.
直到半夜雨才停下来。
It was not until the teacher came in that the students stopped talking.
直到老师进来了，学生们才停止了说话。
2、not until 后边也可以是陈述的句子，如：
It was not until he got sick seriously that he realized the value of a healthy body.
直到他生重病，他才意识到一个健康体魄的价值。
3、not until 后边还可跟介词短语，如：
It was not until after Friday that I got his reply.
直到星期五之后，我才得到他的答复。
