This paper is concerned with the syntactic structure of associative plurals (APs) and in particular APs in those languages that use the ordinary plural marker as the associative marker, dubbed plural pattern languages (e.g. Turkish -lAr functions as both ordinary plural and associative plural on proper names; Ahmet-ler is ambigious between 'multiple Ahmets' and 'Ahmet and his associates'). A novel typological generalization about plural pattern languages is established: they either have affixal definite articles or lack definite articles. In light of this, a new analysis of APs in plural pattern languages is proposed whereby this pattern is derived via movement of the Number head. It is shown that a movement-based approach to the plural pattern both deduces the novel typological generalization and solves a long-standing puzzle regarding a restriction against plural possessor agreement with APs in plural pattern languages.