gq: In Western Catalan, unstressed vowels reduce to five: /e ɛ/ > [e]; /o ɔ/ > [o]; /a u i/ remain distinct. This reduction pattern, inherited from Proto-Romance, is also found in Italian and Portuguese. Some Western dialects present further reduction or vowel harmony in some cases.
Question: What do unstressed vowels reduce to in Western Catalan? Question: Which letters remain distinct? Question: Where did this pattern come from? Question: In what other languages is this pattern found? Question: What do other Western dialects sometimes  offer?