这句话有语病吗？You know, I most love the human is you

以上两位说的部分正确

正确的表达应该是

You know you are the one I love most.

你知道的我最爱的是你

you know是插入语

you是主语 are是系动词 the one（指唯一的那个）是表语 I love most是定语修饰the one。定语前省略who。

You know, the human who I most love is you

You know, the human who I most love is you
你知道，我最爱的人是你
who I most love定语后置，这是英语的习惯用法

别扭啊……

根据原句的意思……

此句应该是有两个句子合并而成的名词性从句。
1、You know that.

2、You are the one whom I most loved.

合并后完整的形式是You know that you are the one whom i most loved.

简写形式就是You know you are the one i most loved.

You know,the person who i love mostly is you.

一般没有用human的，那表示是人类，而不是单指个人。