Tofa is an agglutinative language with a few auxiliary verbs.[1] The bare stem of a verb is only used in the singular imperative; other categories are marked by suffixation, including the singular imperative negative.[3] The Tofa suffix /--sig/ is an especially unusual derivational suffix in that it attaches to any noun to add the meaning 'smelling of + [NOUN]' or 'smelling like + [NOUN]'.[12] Grammatical number in Tofa includes singular, plural, dual inclusive ('you and me'), and plural inclusive, tense includes the present and past, and aspect includes the perfective and imperfective.[3] Historically suffixes conformed to Tofa vowel harmony rules, but that appears to be changing.[3] Some example sentences are included below to illustrate suffixation:[3]