Let's break down why:
* "i" is not a Greek word. It is the English pronoun for "I".
* "adherfi" is not a Greek word. It might be a misspelling of "αδερφή" (aderfi), which means "sister".
* "mu" is not a Greek word either. It might be a misspelling of "μου" (mou), which is a possessive pronoun meaning "my".
It's possible the phrase you are looking for is "η αδερφή μου" (i aderfi mou), which means "my sister".
If you can provide more context or the intended meaning, I might be able to help you with a better translation.