so much nervous为何有错

有个改错题，需要将下面句子中的 much 去掉，请问这里的 much 为何有错？

I was so much nervous that I could hardly tell which direction was left.

much可以修饰动词或形容词/副词的比较级，但不可以修饰形容词/副词原级。比如：

可以说I like it very much. 修饰动词。

He is much better. 修饰形容词比较级。

但不可以说She is much beautiful.

形容词/副词原级要用very，so, too等程度副词修饰.

因此，I was so much nervous that I could...用much修饰形容词原级是语法错误。去掉much, 直接用so强调形容词即可。