热心网友
what可以分解为something+that。例如：I don't understand what you said just now.本句的意思是 I don't understand the words that you said just now.that一般跟在先行词后面。例如：Did you see the letter that came today?letter 在句中就是先行词。that在定语从句中作主语不可省略，但作宾语则可省略。例如：Did you get the book(that)I sent you? that在定语从句中作sent的直接宾语所以可以省略
热心网友
（一）what可以引导名词性从句：（1）宾语从句：I don’t understand what you mean。 我不明白你是什么意思。（2）主语从句：What is needed is a change in land ownership。 所需要的是土地所有制方面的变革。 （二） at可以引导名词性从句：that在主语从句、宾语从句、表语从句和同位语从句中不充当任何句子成分，无词义，不能用which代替,（因为which在这些从句中意为“哪个”。）that在口语化的主、宾、表语从句中可以省略（在同位语从句中不能省略），例如：(1) 主语从句：That you missed such a good film is a pity。 = It’s a pity (that) you missed such a good film。 这样好的电影你没看到真是遗憾。(2) 宾语从句：All the visitors who go there believe that it was right that the temple was rescued。 去那儿参观的人都认为拯救这座庙宇是做得对的。(3) 表语从句：The only problem is (that) you can’t eat trees! 唯一的难题是你不能吃树呀！(4) 同位语从句：They had come from England having heard the strange news that Dr Manette, Lucie’s father, was alive and was living in Paris。 他们听到一个离奇的消息，说露西的父亲曼奈特医生还活着，而且就住在巴黎，就从英国赶来了。 at可以引导（原因、目的、结果）状语从句，一般由that, so that, in order that, so (such) 。。。that等引导，例如：They do this so that people can dry their hair using an electric hair drier! 他们作这些事好让人们能用电吹风吹头发。 at可以引导定语从句，代替人或物，单、复数不变：(1)在从句中作主语时相当于who或which，不能省略。例如： The person that is working is a young worker。 正在工作的那个人是青年工人。(2)在从句中作宾语时相当于whom或which，可以省略。例如： The comrade (that) you saw is a combat hero。 你见到的那位同志是战斗英雄。 at可以引导定语从句，代替表示时间的词，相当于when, 常省略。例如： I laughed and said, “ I seem to remember that the last time ( that / when ) we met I did most of the talking。” 我笑着说：“我记得上次我们见面的时候，好象所有的话都让我一个人说了。” at可以用于强调句型中：It was in Greece that Olympic competitions started。 奥林匹克竞技体育诞生于希腊。。
热心网友
what 引导名词性从句，that引导定语从句