Sentence Processing Among Native vs. Nonnative Speakers: Implications for Critical Period Hypothesis

The present study intended to investigate the processing behavior of 2 groups of L2 learners of English (high and mid in proficiency) and a group of English native speakers on English active and passive reduced relative clauses. Three sets of tasks, an offline task, and 2 online tasks were conducted. Results revealed that the high-proficiency group’s performance was the same as that of the native group in all the 3 tests in terms of accuracy and processing behavior. Accordingly, it was concluded that proficient L2 learners can achieve native-like performance. Also, opposed to maturational propositions on adult L2 learning following the critical period hypothesis, the high-proficiency participants showed native-like behavior on the L2 structures. We suggest that the amount of exposure to an L2 can be a defining factor for L2 learners to perform in a native-like manner.