Abstract
Our study explores how previously acquired languages affect third language (L3) acquisition. The learning and control groups composed adpositional phrases and relative clauses, and then judged sentences with strict/sloppy readings presented in their L3. The results showed that native Japanese learners of Chinese were more influenced by the second language (English) for adpositional phrases and relative clauses than were native Chinese learners of Japanese, although both were influenced more by their native than second language (English) in strict/sloppy interpretation. This indicates that L3 acquisition can be influenced by all previously acquired languages and that the interrelationship between the positions of subgrammars in a sentence structure may influence learners' assessment of the structural similarity of the selected subgrammars, making it an important trigger for non-facilitative transfer. Overall, structural similarities played a stronger role than did typological proximity. This study differs from traditional models of L3 acquisition that focus on wholesale or property transfer by beginning with an investigation of the conditions under which non-facilitative transfers occur. These two perspectives are integrated in terms of cognitive economy, pointing to a more promising direction for L3 acquisition research in the future.