The branches of the Oceanic languages. Orange is the Admiralties languages and Yapese, yellow-orange is St. Matthias, green is Western Oceanic, violet is Temotu, and the rest are Central-Eastern: dark red Southeast Solomons, blue Southern Oceanic, pink Micronesian, and ocher Fijian-Polynesian.
The glottal stop is a leading feature of Yapese. Words beginning with a vowel letter (with a few grammatical exceptions) begin with a glottal stop. Adjacent vowels have the glottal stop between them. There are many word-final glottal stops.
Written Yapese uses Latin script. In Yapese spelling as practised until the 1970s, the glottal stop was not written with an explicit character. A word-final glottal stop was represented by doubling the final vowel letter. Glottalization of consonants was represented with an apostrophe. In the 1970s an orthography was created which uses double vowel letters to represent long vowels; and because of the ambiguity that would occur if the glottal stop was not written, the glottal stop was written with the letter 'q'. This new orthography using the letter 'q' is not in universal use, but many works and maps about Yap represent place names using the orthography and contain amounts of the letter 'q' that are likely to be puzzling to persons not familiar with the language and the new orthography.
Yapese is one of the relatively few languages in the world with ejectivefricatives. The Yapese ejective consonants are /pʼ tʼ kʼ θʼ/. There are also glottalised nasals /mˀ nˀ ŋˀ/ and approximants /jˀ wˀ lˀ/.
In the table below, each phoneme is listed to the left of the grapheme that represents it in Yapese orthography.