Question

The person I want to say thank to most

The person I want to say thank to most is my teacher中副词most前为什么加介词to了？

Answer 1

需要理清两处语法:
一、句中most和to没关系哦。
原因:I want to say thanks to是定语从句，是相对独立的结构，可以理解为I want to say thanks to the person，即，介词to的宾语是the person。
二、most是副词，在句中修饰动词say。

Answer 2

The person I want to say thank to most is my teacher.

我最想(对他)说谢谢的那个人是我的老师。

most副词

Answer 3

The person I want to say thank to most
I want to say thank to 是一个定语从句，修饰person，to的宾语是person most修饰谓语，表示程度。