therefore的两种用法.doc

Therefore的两种用法 一、整句中时一般不放句末，句首后要有逗号句中1、按一般副词使用2、做插入语这两个分得清吧 eg.1、Thereforewe must learn English well. 2、They therefore can learn English well. 3、Many fast food restaurant ,therefore,have red furniture or walls. 二、用在分句中即一个句子一部分表示原因一部分表示结果。 这时一般词前要用分号其后用不用逗号无所谓。若第二个分句前是逗号或无符号则要注意therefore是副词和so不一样要保持句子完整应用and therefore。 eg.1、I had a headache;therefore I could not go to your party. 2、I was ill,and therefore could not come. 3、These birds are very beautiful and therefore liked by many people. However的用发 1. 用作副词 (1) 表示让步意为“无论如何”“不管怎样”用来修饰形容词或副词其词序为however+形容词或副词+主语+谓语。这样用的however其实具有连词的功能用以引导让步状语从句。如 however much he eats, he never gets fat. 不管他吃多少他永远吃不胖。 用于此用法时请注意以下几点 此用法属however所有用法中最重要的考点同学们务请引起高度重视。 这样用的 however 与 no matter how 大致同义。如People always want more, however no matter how rich they are. 人总是富了还想再富。 however No matter how hard I worked, she was never satisfied. 无论我多么努力地工作她从来没满意过。 有时从句谓语可用情态动词。如 Dont laugh, however funny it may be. 无论多么有趣也不要笑。 Ill try to finish it in time, however hard it may be. 无论多么难我也要按时完成。 “however形容词或副词主语谓语”有时可以有所省略。如 I refuse, however favorable the conditions. 不管条件如何有利我都不干。(conditions后省去了are) Id rather have a room of my own, however small (it is), than share a room. 无论房间多么小我宁愿一个人住一间而不愿意与别人合住一个房间。 A grammar rule, however true (it is), is useless unless it can be understood. 一条语法规则不管如何正确除非能懂否则毫无用处。 (2) 表示转折尤其用于谈及一个既成事实时表示转折其意为“可是”“仍然”等。可放在句首、句中或句末通常用逗号与句子其他成分隔开。如 My father, however, did not agree. 但是我父亲不同意。 My room is small; however, its comfortable. 我的房间很小但却很舒服。 He said that it was so; he was mistaken, however. 他说情况如此可是他错了。 表示惊奇或强调相当于how ever的用法其意为“究竟怎样到底以什么方式”。如 however did you get here without a car? 没有汽车你究竟是怎样来