“…With all of this data, researchers have developed detailed and contrasting theories of children's linguistic representations. Researchers have debated whether these representations are syntactic (Bloom, 1970a;Valian, 1986) or semantic (Bowerman, 1978;Goldin-Meadow, 1979), abstract (Fisher, 2002;Valian, Solt, & Stewart, 2009;Yang, 2013) or item-based (Ambridge & Lieven, 2011, 2015Bannard, Lieven, & Tomasello, 2009;Braine, 1976;Tomasello, 2000), present from birth (Crain & Nakayama, 1987;Crain & Thornton, 1998;Hyams, 1994Hyams, , 1996Rizzi, 1994;Santelmann et al, 2002;Wexler, 1994Wexler, , 1998 or maturationally triggered (Borer & Wexler, 1987;Guilfoyle & Noonan, 1992;Radford, 1990;Vainikka, 1993).…”