Avalonian: Phonology: Vowel Quality Inventories: Small (2-4)

Vowel Inventory:

SHORT VOWELS: /i, u, ɛ, ɔ/
LONG VOWELS: /eɪ, oʊ, aɪ, ɑʊ/

Phonetically, the long vowels are
diphthongs but they pattern as long
vowels.