The negative prepositional constructions include two forms of S + Neg + PP + VP and S + PP + Neg+ VP. If the prepositional object is obligatory argument in S + Neg + PP + VP, the unmarked negative focus of the construction is VP. If the prepositional object is optional argument in S + Neg + PP + VP, the unmarked negative focus of the construction is PP. The unmarked negative focus is VP in S + PP + Neg + VP, following the adjacency principle.