Formal:
* A hui hou kākou. (ah-hoo-ee how kah-kow) This is a common and respectful way to say goodbye, meaning "until we meet again."
Informal:
* A hui hou. (ah-hoo-ee how) This is a shortened version of the previous phrase, more casual and suitable for friends or family.
* E ʻike hou kākou. (eh ee-keh how kah-kow) This literally means "we will see each other again."
Romantic:
* E aloha hou kākou. (eh ah-loh-hah how kah-kow) This means "until we love again," and is a more poetic and affectionate way to say goodbye.
The best translation will depend on the specific situation and your relationship with the person you are saying goodbye to.