Based on their longitudinal analysis of the acquisition of Dutch, English, French, andGerman, Klein and Perdue (1997) described a “basic learner variety” as validcross-linguistically and comprising a limited number of shared syntactic patterns interacting withtwo types of constraints: (a) semantic—the NP whose referent has highest control comesfirst, and (b) pragmatic—the focus expression is in final position. These authorshypothesized that “the topic-focus structure also plays an important role in some otherrespects. . . . Thus, negation and (other) scope particles occur at the topic-focus boundary”(p. 318). This poses the problem of the interaction between the core organizational principles ofthe basic variety and optional items such as negative particles and scope particles, whichsemantically affect the whole or part of the utterance in which they occur. In this article, we testthe validity of these authors' hypothesis for the acquisition of the additive scope particlealso (and its translation equivalents). Our analysis is based on the European ScienceFoundation (ESF) data originally used to define the basic variety, but we also included somemore advanced learner data from the same database. In doing so, we refer to the analyses ofDimroth and Klein (1996), which concern the interaction between scope particles and the part ofthe utterance they affect, and we make a distinction between maximal scope—that whichis potentially affected by the particle—and the actual scope of a particle in relation to anutterance in a given discourse context.