Situated within second language (L2) research about the acquisition of morphosyntax, this study investigated English L2 speakers’ detection and primed production of a novel construction with morphological and structural features. We report on two experiments with Thai (n = 69) and Farsi (n = 70) English L2 speakers, respectively, carried out an aural construction learning task that provided low type‐frequency input with the transitive construction in Esperanto—which is marked by accusative case marking (–n) and flexible word order (subject‐verb‐object and object‐verb‐subject)—followed by aural comprehension tests and a priming activity (20 primes and 20 prompts). Results of the aural comprehension tests showed that 23% of the Thai participants (16/69) and 50% of the Farsi participants (35/70) detected the target construction in the input. Results of the primed production task revealed that only those participants who detected the target construction were able to be primed. The findings are discussed in relation to the role of speakers’ previously learned languages in the detection and primed production of novel constructions.

This study investigated whether first language (L1) background and visual information impact the effectiveness of skewed and balanced input at promoting pattern detection. Participants (N = 84) were exposed to Esperanto sentences with the transitive construction under skewed (one noun with high token frequency) or balanced (equal token frequency) input conditions while viewing either color or black-and-white visuals. Their ability to detect the relevant morphological and syntactic features of the transitive construction was tested through a forced-judgment task using novel nouns. The results indicated no significant main effect for visual information or input type. There was, however, a significant main effect for L1 on learners' detection of the novel pattern. Implications are discussed in terms of the potential effect of L1-specific transitive encodings on second language speakers' ability to abstract novel patterns.Constructions are complex assemblies of form-meaning pairings consisting of a fixed, schematic sequence of elements governed by lexical and semantic rules. They are schematic and symbolic in nature and are abstracted from the input through two general cognitive processes: similarity reasoning (e.g., identifying a concrete feature that all exemplars have and finding a relational structure across the exemplars) and analogical reasoning (e.g., finding an underlying structure that all exemplars follow; Gentner & Markman, 1997). These cognitive processes are believed to promote pattern detection and abstraction, which can be facilitated through exposure to low-variability input, which is input with little lexical diversity or low type frequency (