Adults learning a new language tend to judge unconventional utterances more leniently than fluent speakers do; ratings on acceptable utterances, however, tend to align more closely with fluent speakers. This asymmetry raises a question as to whether unconventional utterances can be statistically preempted by conventional utterances for adult…

Evidence from usage-based studies of second language (L2) acquisition reveals that a main source of L2 learners' developing grammars is the L2 input to which learners are regularly exposed. What learners develop from their extended engagement in the sequences of actions comprising the input is not an acontextual system of grammatical units but…