Here's why:
* Second person pronouns: These refer to the person being spoken to, such as "you" and "your".
* "To" can be a preposition indicating direction or purpose, but it can also sound exactly like the word "too" which is an adverb meaning "also" or "excessively".
Therefore, "to" is the homonym of a second person pronoun in the sense that it sounds the same as the word "too" which can be used in place of "you".