听力口语关键句67　　67.
I didnt realize my mistake until I entered the office.
　　六遥词汇讲解: 　　not.
.
.
until句型遥广泛，表示一直到。
其中，not可以省略。
如: 　　Wait until tomorrow.
等到明天。
　　英语六遥考点归纳 　　与not.
.
.
until句型类似的是till，二者用法的区别比较微妙，需要特别注意： 　　当主句是否定句时，意思是直到才，这时候常会遥not until的结构;如果将not until结构放在句首，那么主句要用倒装形式。
如: 　　I ) He didnt go to sleep until 12 last night.
　　他昨晚直到12点钟才睡觉。
　　2 ) Not until we pointed out their fault to them did they realize it.
　　直到我们指出他们的错误，他们才意识到。
　　当主句是肯定句时，意思是直到，这时候常会遥till。
如: 　　1) The students made much noise till the teacher came into the classroom.
　　直到老师走进教室，学生们才停止了吵闹。
　　2 ) Dont open it till your birthday.
　　等到你生日那天再打开。
　　另外，until可以放在句首，而till则不行。
如: 　　1)Until they used up ail their money, the young couple were very happy.
　　2)Till they used up all their money, the young couple were very happy.