“…Comprehension paradigms, such as preferential-looking or pointing, have found evidence for syntactic abstractions for transitive structures as early as 1;7 (e.g., Dittmar et al, 2011;Naigles, 1990;Yuan et al, 2012). In contrast, naturalistic observations (e.g., Tomasello, 1992) and production paradigms, including weird word order, nonce verb and syntactic priming studies (Bencini & Valian, 2008;Brooks & Tomasello, 1999;Kemp et al, 2005;Matthews et al, 2005;Miller & Deevy, 2006;Shimpi et al, 2007;Stumper & Szagun, 2008; but see Franck et al, 2011) have found evidence for abstract syntactic representations only from around three years of age. Usage-based-constructivist accounts suggest that comprehension tasks require merely weak syntactic knowledge derived from fewer exemplars (Abbot-Smith et al, 2004;Dittmar et al, 2008), and thus do not robustly test for syntactic productivity.…”