Singular disjunctive coordinate nouns in MG and in a number of other languages is interesting since the verb can show either singular or plural agreement. This variation is seen as the result of an analysis of the disjunction or either as 'inclusive' or 'exclusive' in truth-conditional semantics. We will support that the variation in verb agreement is contextually motivated and therefore it is immediately related to the contextual interpretation of the disjunctive coordinate phrase either as an 'exclusive' (singular) interpretation or as an 'and-coordinate' (plural) interpretation. Our proposal will predict both verb agreement forms in singular disjunctive nouns taking into account the various discourse conditions, and combining λ calculus and the DRT theory, known as λ-DRT.