Previous research has suggested that Event-Related Potentials (ERPs) can index form-, meaning-, and use-related aspects of the second language (L2) vocabulary knowledge, through, respectively, a lexical decision task (LDT, targeting N400), a semantic relatedness task (SEMREL, targeting N400), and a grammatical judgment task (GJT, targeting P600/AN). Yet, those findings were established in the context of either laboratory-based or longitudinal word learning studies. Therefore, this conceptual replication study investigates whether LDT, SEMREL, and GJT could reveal the aforementioned ERP components in the context of an ecologically valid short-term intervention representative of L2 classroom practice. Twenty Dutch-speaking participants performed reading and writing tasks in a computer-assisted learning environment. Target words were 20 real L2 French verbs. ERPs were recorded immediately after the learning sessions. Results showed N400 for form- and meaning-related knowledge and P600 for grammatical use. We conclude that ERPs can index L2 vocabulary knowledge gained through ecologically valid classroom activities.