Tone alternation in Dàgáárè verbs: Perfectives and Imperfectives

While previous studies on Dàgáárè tone have looked at the nouns, this paper particularly examines tone in verbs, perfective vs imperfective forms. The verbal system has different patterns based on the form of the verb. There are three tone classes for Dàgáárè verbs and for each of the classes, the surface tone pattern it exhibits in the perfective is systematically different from the tone patterns in the imperfective. For the perfectives we have L, H and HL while the imperfectives have LH, HL and H!H, at least in the dialect under study. I treat tone as a combination of the features [±upper] and [±raised] which are connected to what is described as a Tone node (T-node). These Tone nodes in turn connect to the syllable. Under this system, I assume L is represented with the features [-upper] and [-raised] and H with the features [+upper] [+raised]. Underlying tonal melodies of the root morphemes are identical to the surface tones of the perfective forms whether these contain an overt suffix or not. For the imperfectives, the suffix comes with an unspecified underlying T-node. The grammar then chooses the features [±upper] and [±raised] to insert under the already existing T-node.