* Keiki kāne: This is the most common way to say "boy" in Hawaiian. It literally means "male child".
* Keiki: This simply means "child" and can be used for both boys and girls.
* Kānaka: This means "person" and can be used for both men and women. You could use it in a context where it is clear you are referring to a male child.
The best way to say "boy" in Hawaiian depends on the context and your intended meaning.