Keresan words, only a glottal stop /ʔ/ ⟨ʼ⟩ can close a syllable, but some loanwords from Spanish have syllables that end in a consonant, mostly a nasal (i.e. /m n/ but words containing these sequences are rare in the language. Due to extensive vowel devoicing, several Keresan words may be perceived as ending in consonants or even containing consonant clusters. Word-internal cluster: yʼâakạ srûunị ‘stomach’ /jˀɑ̂ːkḁʂûːni/ > [jɑ̂ːkḁʂûːni] ~ [jɑ̂ːkʂûːni] Word-final coda: úwàakạ ‘baby’; /úwɑ̀ːkḁ/ > [úwɑ̀ːkʰḁ] ~ [úwɑ̀ːkʰ] Phonotactics The only sequence of consonants (i.e. consonant cluster) that occurs in native Keresan words is a sequence of a fricative /ʃ ʂ/ and a stop or affricate. Clusters are restricted to beginnings of syllables (i.e. the syllable onset). When the alveolo-palatal consonant /ʃ/ occurs as C1, it combines with alveolar and palatal C2, whereas the retroflex alveolar /ʂ/ precedes bilabial and velar C2s, which suggest a complementary distribution. Consonant clusters may occur both word-initially and word-medially. Orthography Traditional Keresan beliefs postulate that Keres is a sacred language that must exist only in its spoken form. The language's religious connotation and years of persecution of Pueblo religion by European colonizers may also explain why no unified orthographic convention exists for Keresan. However, a practical spelling system has been developed for Laguna (Kʼawaika) and more recently for Acoma (Áakʼu) Keres, both of which are remarkably consistent. In the Keres spelling system, each symbol represents a single phoneme. The letters ⟨c q z f⟩ and sometimes also ⟨v⟩ are not used. Digraphs represent both palatal consonants (written using a sequence of C and ⟨y⟩), and retroflex consonants, which are represented using a sequence of C and the letter ⟨r⟩. These graphemes used for writing Western Keres are shown between ⟨...⟩ below. Consonant symbols Signage at Acoma Pueblo Signs at Acoma Pueblo sometimes use special diacritics for ejective consonants that differ from the symbols above, as shown in the table: Vowel symbols Vowel sounds are represented straightforwardly in the existing spellings for Keresan. Each vowel sound is written using a unique letter or digraph (for long vowels and diphthongs). However, there are two competing representations for the vowel /ɨ/. Some versions simply use the IPA ⟨ɨ⟩ whereas others use the letter ⟨v⟩ (the sound /v/ as in veal does not occur in Keresan). Voiceless vowels have also been represented in two ways; either underlined or with a dot below (see table). Diacritics for tone