so 形容词 a 单数名词 that 从句为什么要加上a和可数名词，我觉得不加也没什么呀！希望举例

\u6709\u8fd9\u79cd\u7528\u6cd5\u5417\uff0c\u8bf7\u4e3e\u4f8b\u8bf4\u660eso +\u5f62\u5bb9\u8bcd+ a/an+\u540d\u8bcd\u5355\u6570\u5f62\u5f0f+ that\u4ece\u53e5;\u8c22\u8c22\u5404\u4f4d

The book is SO good THAT you must read it ==It is SUCH a good book THAT you must read it.
(\u6ce8\u610f\uff0c\u53ea\u80fd\u5728\u53ef\u6570\u540d\u8bcd\u5355\u6570\u65f6\u53ef\u4ee5\u4ea4\u6362\u6539\u5199\u3002)

so+\u5f62\u5bb9\u8bcd+\u53ef\u6570\u540d\u8bcd\u5355\u6570,\u5b9a\u8bed\u4ece\u53e5\u4e2d
\u8be5\u53e5\u578b\u7b49\u4e8esuch+a+\u5f62\u5bb9\u8bcd+\u540d\u8bcd\u5355\u6570+that
Facing so large an audience that the young actress choked up.
\u9762\u5bf9\u8fd9\u4e48\u591a\u542c\u4f17,\u90a3\u4e2a\u5e74\u8f7b\u6f14\u5458\uff08\u7d27\u5f20\u5f97\uff09\u8bf4\u4e0d\u51fa\u8bdd\u6765.
It is so beautiful a scenery that many people look lost in it.
\u666f\u8272\u5982\u6b64\u4f18\u7f8e,\u5f88\u591a\u4eba\u90fd\u770b\u5446\u4e86.

看so的句型： so+形容词/副词原形+that +句子
so+形容词原形+a/an+名词单数=such a/an +形容词原形+名词单数
so that +句子
如果要表达她是如此好的一个女孩，以至于我们每个人都喜欢她
一个必须要a的
She is so good a girl that everyone of us likes her

可以，只能加形容词，因为一般情况下只有形容词修饰名词。
eg.such
an
interesting
book
such
clean
water（water为不可数名词
such+adj.+不可数名词）
p.s.该结构可与so+adj.+a（n）+名词（单数）互换
eg.so
interesting
book
so
clean
water
不懂可追问，望采纳、

不加的话，so that放一起就是“为了……”的意思。

你是真一点常识都没有啊

扩展阅读：网络语soso啥意思 ... so和such用法顺口溜 ... a so加形容词加名词 ... a单数名词or two ... so加形容词加复数名词 ... so 形容词 that ... so和such的句型结构 ... so+形容词 ... such a形容词可数名词单数 ...