ʻOkina

The ʻokina (Hawaiian pronunciation: [ʔoˈkinɐ]) is the letter that transcribes the glottal stop consonant in Hawaiian. It does not have distinct uppercase and lowercase forms, and is represented electronically by the modifier letter turned comma: ʻ.

A phonemic glottal stop exists in many other Polynesian languages as well; these are usually written by a similar apostrophe-like letter.