irrealis future suffix -laha- indicates that the action will certainly occur, whereas the irrealis future suffix -laho- does not provide such certainty. Consonants Koasati has the consonants given in the table below, based on Geoffrey Kimball's work. IPA transcriptions occur in brackets when different from the orthography provided by Kimball. Not included in this chart is a glottal glide (marked :) that Kimball uses in his own consonant chart, presumably to represent the lengthened vowel sounds of Koasati. In the Tribe's official orthography, the is represented by and the is represented by , with no distinction for aspiration. Additionally, Kimball notes that and are aspirated in initial and medial positions. However, the website for the Koasati Language Project explicitly states that these consonants are never aspirated. The occurs most often before , as in "river", spelled in the official orthography, thereby distinguished from "tail". Syllable structure Koasati has both light (CV, VC, V) and heavy (CVC) syllables. Consonant clusters occur across syllables but not within. All monomorphemic Koasati words end in light syllables, while the penultimate syllable can be light but is usually heavy, and it is usually preceded by one or more light syllables, as with the construction CV.CVC.CV as in the word holihtá "fence". Other shapes, in which one or more heavy syllables precede a heavy penultimate syllable (e.g. CV.CVC.CVC.CV as in hacokpalpá "butterfly"), or alternate heavy and light syllables (e.g. CVC.CV.CVC.CV. as in pa:piyá:ka "bridge"), are usually the result of the compounding of two words or a once-productive rule of syncope in which the vowel of every second syllable except the final syllable was deleted. Vowel clusters occur in Koasati, unlike in other Muskogean languages where such clusters are made impossible by metathesis and vowel deletion. These clusters occur in Koasati due to the use of locative prefixes that end in a vowel and class 1A negative transitive verbs since these do not undergo the processes of metathesis and vowel deletion. Clusters beginning with /a:/ and /i:/ are most frequent, and all clusters are generally spoken with a glottal stop between vowels. Tone Koasati has low [ ` ], high [ ´ ], and high rising–falling [ ˇ ] pitch accents, as well as a fourth unmarked mid-level tone. All noun roots must have one high-pitch accented syllable. The location of the accent depends on the properties of the penultimate syllable. With a few exceptions, the accent