This study investigated whether second language (L2) speakers' morphosyntactic pattern learning was predicted by their statistical learning and working memory abilities. Across three experiments, Thai English as a Foreign Language (EFL) university students (N = 140) were exposed to either the transitive construction in Esperanto (e.g., tauro batas cevalon, "bull hits horse") or the nonprototypical English double-object dative construction (e.g., John built the table a leg). They also completed an aural test of statistical learning and a spoken backward digit-span test of working memory. In Experiment 1, only statistical learning was predictive of Esperanto pattern learning. Experiment 2 targeted pattern learning of the English nonprototypical double-object dative construction. Although working memory was associated with performance in the exposure phase, only statistical learning predicted test performance, as in Experiment 1. Finally, Experiment 3 served as a control condition in which participants were exposed to prototypical datives only during the exposure phase. This experiment showed that neither statistical learning nor working memory were associated with exposure or test performance. The findings are discussed in terms of the engagement of statistical learning and working memory during L2 pattern learning.Keywords: L2 pattern learning; statistical learning; working memory CONSTRUCTION LEARNING STUDIES CARried out by Goldberg and colleagues have shown that first language (L1) speakers of English can comprehend and produce the novel construction of appearance (N 1 N 2 V), with the corresponding meaning of N 1 'appears in/on' N 2 (e.g., the spot the king moopoed) after relatively brief language exposure (Boyd, Gottschalk, & Goldberg, 2009;Casenhiser & Goldberg, 2005;Goldberg & Casenhiser, 2008;Goldberg, Casenhiser, & Sethuraman, 2004;Goldberg, Casenhiser, & White, 2007). However, construction learning studies with second language (L2) speakers have reported far greater variability with a variety of constructions, including the appearance construction and Samoan ergative constructions (Nakamura, 2012), Esperanto transitives (Fulga & McDonough, 2016;McDonough & Fulga, 2015;McDonough & Trofimovich, 2013, 2015, and English datives (McDonough & Nekrasova-Becker, 2014;Year & Gordon, 2009). These studies have shown that L2 speakers experience considerable difficulty when learning new patterns. Researchers have speculated that a variety of factors may account for this difficulty, including the explicitness of the classroom learning environment