固有振動
Mode indicates when the action happens. Normal mode is also referred to as tense, and is given by mode/aspect prefix positions in the verbs. The tense modes are the imperfect (present), perfect (past) and the future represented by 4 types of imperfectives—∅, z, n, gh—and 4 types of perfectives—gh, z, n, ∅. There are also 4 modal variations: neuter, inceptive, optative-intentional, and negative.