Based on their longitudinal analysis of the acquisition of Dutch, English, French, and German, Klein and Perdue (1997) described a “basic learner variety” as valid cross-linguistically and comprising a limited number of shared syntactic patterns interacting with two types of constraints: (a) semantic—the NP whose referent has highest control comes first, and (b) pragmatic—the focus expression is in final position. These authors hypothesized that “the topic-focus structure also plays an important role in some other respects. . . . 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 of the basic variety and optional items such as negative particles and scope particles, which semantically affect the whole or part of the utterance in which they occur. In this article, we test the validity of these authors' hypothesis for the acquisition of the additive scope particle also (and its translation equivalents). Our analysis is based on the European Science Foundation (ESF) data originally used to define the basic variety, but we also included some more advanced learner data from the same database. In doing so, we refer to the analyses of Dimroth and Klein (1996), which concern the interaction between scope particles and the part of the utterance they affect, and we make a distinction between maximal scope—that which is potentially affected by the particle—and the actual scope of a particle in relation to an utterance in a given discourse context