Sesotho is one of the African Languages, where sentence negation is expressed by means of bound negative morphemes. It has only three negative morphemes which are spread across the Sesotho matrix and subordinate clauses. They are the negative morphemes /ha/, /sa/ and /se/. These morphemes are bound verbal morphemes that negate various predicate form sand only appear in restricted sentence types. The central aim of this paper is to examine sentence constructions that realize negation by means of negative morphemes /se/ and its syntactic distribution within copulative verbs, non-copulative verbs, deficient verbs and aspect morphemes over a full range of inflectional categories such as tense, aspect and mood. This morpheme will be examined within the general framework of the Minimalist Program, which holds that inflectional categories occur as heads of phrasal categories. This paper will further illustrate the morphological representations of these morphemes within Beard (1995)'s Lexeme-Morpheme Base Morphology.