Colley F. Sparkman

Portuguese versus Spanish Written Accents and Diphthongs in Rules for Stress

(2) Stress the last syllable (unless otherwise indicated by a written accent): (a) of all words ending in 1, r, z, i (is), u (us); (b) of all words that have two vowels preceded by a consonant in the last syllable, in all of which (except in words ending in I or r) the first vowel must be emphasized; (c) of all words that have a nasal vowel in the last syllable (indicated either by the tilde or by the syllables ending in m or ns) except words ending in am, em, or ens: