英语语法It's unfair that judging a man only by his appearance.这句话语法错在哪里

Question

句酷作文一直提示这句话语法错误，可我不知道错在哪里。事实上我不认为这句话错了。

Answer 1

that 后面跟的应该是一个句子，但是这句话后面跟的是一个由动名词连接的短语，正确的句子应该是：It's unfair that judge a man only by his appearance.或者It's unfair to judge a man only by his appearance.