In Leonese , any of five vowel phonemes , \ / a , e , i , o , u \ / , may occur in stressed position , and the two archiphonemes \ / I \ / , \ / U \ / and the phoneme \ / a \ / may occur in nonstressed position , spelled with e , u , a at the end of word .
The language has a system with five vowels in a stressed position , represented by a , e , i , o , and u and three ( two archiphonemes \ / I \ / , \ / U \ / and one phoneme \ / a \ / ) in non-stressed position , represented by e , u , and a at the end of word .