Ylysepen has 9 vowels. Each front vowel has a back counterpart, each close vowel has a mid counterpart, and each unrounded vowel has a rounded counterpart. The only exception is "a" which has none.

Front Back
Close i • y ɯ • u
Mid e • ø ʌ • o
Open a

Most vowels are represented by one sound. A few can be represented in multiple ways depending on context.

Phoneme Letter(s) Examples
i é • i kim, énur
y y yly, kyg̈
ɯ w owre, lwken
u u um, uabl
e á • e tenerát, njámju
ø o̧s, korgo̧
ʌ u • e • a kurgis, tjikle, talura
o o koner, owre
a a saa, zvaren