as/ because/ for/ since Ⅰ. 这三个词都可以用作连词,表原因、理由 但有区别: Ⅱ. as 因为、既然表示的原因或理由是明显的。语意不如because强。当理由是明显的,或者被认为是已知的时,则以用as 为好。如: ① As he was not well, I decided to go without him. 因为他身体不好,我决定独自去了。 ② As it was getting very late, we soon turned back. 因为已很晚了, 我们很快就回来了。 ③ As it is raining, youd better take a taxi. 既然在下雨,你最好乘出租车。 Ⅲ. because 因为表直接而明确的原因或理由。即必然的困果关系。在这几个词中,它的语意最强。回答以why 引导的特殊疑问句时,只能用because . 注意:because 不可以与so 连用。如: ① He had to stay at home yesterday because he was ill. 昨天他只得呆在家里,因为他病了。 ② I did it because they asked me to do it. 我之所以做这件事,是因为他请我做的。 ③ ---Why cant you do it now? --- Because Im too busy. Ⅳ. since既然比as 较为正式,说明为人所知的原因。语气比because 稍弱。 |