five stressed vowels () and three unstressed vowels, with merging into and merging into . Unlike Neapolitan, Catalan or Portuguese, Sicilian incorporates this vowel reduction into its orthography. Catalan Catalan has seven or eight vowels in stressed syllables and three, four or five vowels in unstressed syllables, depending on dialect. The Valencian dialect has five, as in Vulgar Latin. Majorcan merges unstressed and , and central Catalan further merges unstressed and . Portuguese Portuguese has seven or eight vowels in stressed syllables (). The vowels and , which are not phonemically distinct in all dialects, merge in unstressed syllables. In most cases, unstressed syllables may have one of five vowels (), but there is a sometimes unpredictable tendency for to merge with and to merge with . For instance some speakers pronounce the first syllable of dezembro ("December") differently from the first syllable of dezoito ("eighteen"), with the latter being more reduced. There are also instances of and being distinguished from and in unstressed syllables, especially to avoid ambiguity. The verb pregar ("to nail") is distinct from pregar ("to preach"), and the latter verb was historically spelled prègar to reflect that its unstressed is not reduced. Portuguese phonology is further complicated by its variety of dialects, particularly the differences between European Portuguese and Brazilian Portuguese, as well as the differences between the respective dialects of the two varieties. Slavic languages Bulgarian In the Bulgarian language the vowels а [a], ъ [ɤ], о [ɔ] and е [ɛ] can be partially or fully reduced, depending on the dialect, when unstressed to [ɐ], [ɐ], [o] and [ɪ], respectively. The most prevalent is [a] > [ɐ], [ɤ] > [ɐ] and [ɔ] > [o], which, in its partial form, is considered correct in literary speech. The reduction [ɛ] > [ɪ] is prevalent in the eastern dialects of the language and is not considered formally correct. Russian There are six vowel phonemes in Standard Russian. Vowels tend to merge when they are unstressed. The vowels and have the same unstressed allophones for a number of dialects and reduce to a schwa. Unstressed may become more central if it does not merge with . Other types of reduction are phonetic, such as that of the high vowels ( and ), which become near-close; этап ('stage') is pronounced , and мужчина ('man') is pronounced . Early Slavic languages Proto-Slavic had two short high vowels known as yers: a