This collection of studies by leading scholars in the field focuses on the semantics of non-definite (bare and indefinite) plural NPs. The contributions in the first part concentrate on bare plurals and their cross-linguistic counterparts. They discuss applicability of the notion of 'semantic incorporation' to bare plurals by contrasting them to bare singulars, with the aim of accounting for the interaction between the semantics of number and the degree of (in)dependency of the NP with respect to the verb. The articles in the second part examine the relationship between the semantics of number and the semantics of aspect. The contributions in the third part concentrate on non-definite numerical noun phrases by addressing a range of fundamental questions such as: the semantics of indefinite time-phrases, numericals in classifier- and non-classifier languages, scope interactions, the at least- and exactly-readings, referential properties of numericals. The volume will be welcomed by linguists interested in the semantics of number in non-definite NPs.