It's a very very difficult dream to achieve.句式结构是什么

It's a very very difficult dream to achieve.句式结构是什么
It's a very very difficult dream to achieve.句式结构是什么

It's a very very difficult dream to achieve.句式结构是什么
It形式主语 's谓语 a very very difficult dream 表语 to achieve真正的主语

主谓结构
这是一个 很难实现的梦想

It（主语）is（谓语） a very very difficult dream （表语）to achieve（定语）.

It是主语，is是系动词（谓语），a very very difficult dream是表语，to achieve是不定式作后置定语。