so..that..是固定用法,意为：“如此.以至于.”
如果单独看that的话,它就是一个普通的连接词.去掉so可以吗可以的the book is nice that is what i want（to buy）这个句子正确吗？不正确，要在that之前加一个and就对了the book is nice andthat is what i want（to buy）.the book which is nice is i want（to buy）the book which is nice that is what i want（to buy）这两个句子怎么分析呢？哪个对？两句话都不正确。第一句：the book which is nice is i want（to buy） 这句话你用which引导一个定语从句修饰book，这儿没错。错的在后面，the book which is nice is后面连接的是表语从句，缺少一个词来引导这个表语从句，所以要加个what。the book which is nice is what i want（to buy）第二句：根据我对第一句的分析，很容易发现这句多了一个连接词that，删去就行了。