Simon learned ASL as his L1 from parents who had learned it as an L2 after puberty and provided him with imperfect models .
Singleton and Newport ( 2004 ) demonstrate the function of UG in their study of ' Simon ' .
Simon learned ASL as Simon 's L1 from parents who had learned it as an L2 after puberty and provided him with imperfect models .
Singleton and Newport ( 2004 ) demonstrate the function of UG in their study of ' Simon ' .