be to be 为什么可以表将来?

主要表示按计划按照安排将要做的事情。be to +动词不定式中的be to用作情态习语,这时的be to do表示:“计划”、“安排”He is to have a holiday。(表示将来) The committee is to meet today。(表示计划、安排) You are to go to the hotel where rooms have already been booked for you。1。表示 “将”、“计划”、“安排”。(意思接近于be going to) 如：Their daughter is to get married soon。Who is to question him?It was the last film at the cinema,which was to close next day。After dinner they were to go to a movie。was/ were to do 表示过去曾经计划要做的事,或者过去应当做的事,而且从现在的角度来看已经实现了。如：I felt nervous because I was soon to leave home for the first time。I was to play Juliet。The expedition was to start in a week’s time。was/ were to have done,表示 “本打算”、“本计划”或“本应当” 做的事而没有做成或没有发生。如:I was to have seen him last Wednesday,but he didn’t come。We were to have been married last year。