Abstract In Tagle, verbal number, as realized by singular and plural stems, has not only aspectual functions in expressing single and multiple events. Verbal number also serves as a morphosyntactic device encoding specific grammatical relations : The selection of a singular or plural stem is sensitive to the number of the intransitive subject (S) and the transitive object (P) participant. In derived ditransitive applicative constructions, the stem selection depends on the semantic roles of the two object participants. When they are assigned the roles of Beneficiary (B) and Theme (T), it is the number of the direct object T (rather than the indirect/applied object B) which selects a singular or plural stem. When assigned the roles of Experiencer (Exp) and T, however, the Exp (rather than T) interacts with verbal number. When comparing the two ditransitive objects of the Beneficiary construction, B and T, to the object P and when taking their interaction with verbal number as parameter of the comparison, one finds that T and P (rather than B) interact with verbal number. The alignment of T with P and the non-alignment of B can be identified as indirect object construction, T = P ≠ B. However, when the Exp role is assigned to the indirect/applied object and the T role to the direct object, Exp (rather than T) selects the singular or plural stem, i.e. Exp behaves like P. This alignment pattern, Exp = P ≠ T, is known as secondary-object construction.