是否对你承诺了太多
还是我原本给的就不够

The lyric says:
Did I promise too much
Or did I not give you enough in the first place

In here, 本 is that word that people use to describe the root cause of something that is happening now.
So, today let’s expand your vocabulary with this character, 本, the root, the source and the self.

The character has 3 layers of meanings, the first one is the root of plants, the words:
本草纲目 and 无本之木 are both referred back this original meaning.

And this character over time derived its 2nd layer of meaning, the source, the origin, and the foundation.
本意, intention
本来, original
根本, fundamental, or absolute
基本, basic
本体, torso, the main part
本质, the intrinsic quality, or the essence
本能, instinct
本性, human nature

And going further, this character has its 3rd layer of meaning, the self, or something considered from a self-perspective.
本人, the self.
本国, the native country.
本土, the mainland, or the local terrortory
本身, in itself.
本位, self-perspective.
本分, obligation or duty.

And lastly, there is a fixed use for this character to refer to and count books.
一本书, a book.
书本, books.