(1) shall / will + 动词原形。表示马上发生的动作或存在的状况。尤其是表示客观性的事情或在某条件下要发生的事情，只可以用此结构。如：What shall we do if he doesnt come? 假如他不来，大家该如何解决？Will you be free this evening? 今天晚上有空吗？I think he will tell us the truth. 我想他会告诉大家真实状况的。(2) be going to + 动词原形。表示已经计划或安排好了的事情，也可表示有迹象显示一定要发生的事情。如：We are going to have a meeting to discuss the matter this evening. 今天晚上开会讨论这件事情。Look at the black clouds over there. I think it is going to rain soon. 看一看那边的乌云，我想天要下雨了。There is going to be an English evening this week. 本周要举行一个英语晚会。(3) be to + 动词原形。表示一种常规性的活动或注定要做的事情。如：Who is to clean the classroom today? 今天该哪个打扫教室了？When are you to return your library book? 你什么时间要还图书？The bridge is to be completed by the end of this year. 这渡桥该在今年年底前完工。(4) be about to + 动词原形。表示就要做或正好要做的事情。总是暗含一种时间上的巧合，因此，句子不可以再用时间状语。如：Dont leave. Li Lei is about to come. 不要走了，李蕾就要来了。Be quiet. The concert is about to start. 安静下来，音乐演唱会就要开始了。(5) be +目前分词。表示马上发生的动作或存在的状况。这个句型中动词主如果瞬间动词：come, go, leave, arrive, begin, start, sTOP, close, open, die, join, borrow, buy等。如：Go ahead, and Im coming. 走前面一点吧，我就来。The dog is dying. 那条狗要去世了。Hurry up. The shop is closing. 快点，商店就要关门了。(6) 一般目前时。表示一种严格根据计划进行的动作。比如，上课、飞机起飞、火车离站等。如：Dont hurry. The meeting starts at a quarter past eight. 不要匆忙，回忆八点过一刻开始。The bus goes back at four thirty. 汽车四点返回
