Until直到….为止,肯定形式表示的意思是"做某事直至某时",动词必须是延续性的.
I slept until midnight.我一直睡到半夜时醒了.
选when,当,时候
本题可以写,you don't know the result until everybody has finished their work
not until直到…才,否定形式表达的意思是"直至某时才做某事".动词为延续性或非延续性都可以.
She didn”t arrive until 6 o”clock.
她直到6点才到.
Don”t get off the bus until it has stopped.
公共汽车停稳后再下车.
I didn”t manage to do it until you had explained how.直到你教我后,我才会做.