there are many cases where some other vowel was used, and the orthographic rules for this are only partially understood; this is largely due to the difficulty in ascertaining whether this vowel may be due to an underspelled suffix. proposed the following conventions: A CVC syllable was written CV-CV, where the two vowels (V) were the same: yo-po [yop] 'leaf' A syllable with a long vowel (CVVC) was written CV-Ci, unless the long vowel was [i], in which case it was written CiCa: ba-ki [baak] 'captive', yi-tzi-na [yihtziin] 'younger brother' A syllable with a glottalized vowel (CVʼC or CVʼVC) was written with a final a if the vowel was [e, o, u], or with a final u if the vowel was [a] or [i]: hu-na [huʼn] 'paper', ba-tzʼu [baʼtsʼ] 'howler monkey'. Preconsonantal [h] is not indicated. In short, if the vowels are the same (harmonic), a simple vowel is intended. If the vowels are not the same (disharmonic), either two syllables are intended (likely underspelled), or else a single syllable with a long vowel (if V1 = [a e? o u] and V2 = [i], or else if V1 = [i] and V2 = [a]) or with a glottalized vowel (if V1 = [e? o u] and V2 = [a], or else if V1 = [a i] and V2 = [u]). The long-vowel reading of [Ce-Ci] is still uncertain, and there is a possibility that [Ce-Cu] represents a glottalized vowel (if it is not simply an underspelling for [CeCuC]), so it may be that the disharmonies form natural classes: [i] for long non-front vowels, otherwise [a] to keep it disharmonic; [u] for glottalized non-back vowels, otherwise [a]. A more complex spelling is ha-o-bo ko-ko-no-ma for [haʼoʼb kohknoʼm] 'they are the guardians'. A minimal set is, ba-ka [bak] ba-ki [baak] ba-ku [baʼk] = [baʼak] ba-ke [baakel] (underspelled) ba-ke-le [baakel] Verbal inflections Despite depending on consonants which were frequently not written, the Mayan voice system was reliably indicated. For instance, the paradigm for a transitive verb with a CVC root is as follows: The active suffix did not participate in the harmonic/disharmonic system seen in roots, but rather was always -wa. However, the language changed over 1500 years, and there were dialectal differences as well, which are reflected in the script, as seen next for the verb "(s)he sat" ( is an infix in the root chum for the passive voice): Emblem