Language researchers and teachers have long been interested in the timing of learning, and the distributed practice effect, whereby greater inter-session intervals result in longer retention, is well-known (Kim & Webb, 2022). Many L2 studies have focused on the intentional learning of lexis (Edmonds, Gerbier, Palasis, & Whyte, 2021), neglecting implicit learning and syntactic development (Rogers, 2021). The present project includes both explicit vocabulary learning activities and incidental exposure to a complex syntactic structure via a bespoke online L2 English learning platform. The goal is to investigate the two types of learning in two spacing conditions. This paper describes (1) the learning activities created to present opportunities for explicit vocabulary learning and the concealed syntactic input, and (2) the tests used to evaluate participants' receptive and productive knowledge of target items. It aims to inform computer assisted language learning design with respect to pedagogical progression, learning activities, feedback, and learning schedules. [For the complete volume, "Intelligent CALL, Granular Systems and Learner Data: Short Papers from EUROCALL 2022 (30th, Reykjavik, Iceland, August 17-19, 2022)," see ED624779.]