对很多人来说,时态是他们学习英语道路上的一个拦路虎,大家都知道使用汉语句子表达时不需要考虑动词时态,但英语和汉语完全不同,不仅简单句要考虑时态问题,复合句更要考虑时态问题。
例如时间状语从句和条件状语从句,这两种复合句的时态就要遵循主将从现的语法规则,而主将从现规则常见有三种句型结构,具体内容如下:
句型结构一:主句是一般将来时态,从句用一般现在时态
例句:Mary won't ask you to go to the park with her if you are busy doing homework.
译文:如果你忙于做家庭作业,玛丽就不会让你和她一起去公园。
例句:Mike is going to be a scientist when he grows up.
译文:迈克长大时打算成为一名科学家。
例句:I will call you back as soon as he leaves for Beijing.
译文:他一动身去北京,我就会给你回电话。
句型结构二:主句是祈使句,从句用一般现在时态
例句:Don't forget to eat breakfast before you go to school in the morning.
译文:早上上学之前不要忘记吃早餐。
例句:Never bother her when she practices playing the piano.
译文:当她练习弹钢琴时,绝不要打扰她。
例句:Please look them up in the dictionary if you don't know these new words.
译文:如果你不认识这些新单词,那就请查阅一下词典吧。
句型结构三:主句谓语有情态动词,从句用一般现在时态
例句:Mary can't go on a picnic with them if she has a lot of work to do this weekend.
译文:如果玛丽这个周末有许多工作要做的话,她就不可能和他们一起去野餐。
例句:You mustn't leave the classroom in advance unless your teacher gives you his permission.
译文:除非你获得老师的同意,否则你不得提前离开教室。
例句:They may go on a trip to the Great Wall for free as long as they finish the work on time.
译文:只要他们按时完成工作,他们就可以免费去长城旅游。
以上就是有关主将从现的三种句型结构,应用的范围就是状语从句,大家一定要搞清楚,千万不要用在其它类型的复合句身上。