Judgment tasks (JTs, often called acceptability or grammaticality judgment tasks) are found extensively throughout the history of second language (L2) research. Data from such instruments have been used to investigate a range of hypotheses and phenomena, from generativist theories to instructional effectiveness. Though popular and convenient, JTs…

Age of acquisition (AoA) refers to the age at which people learn a particular item and the AoA effect refers to the phenomenon that early-acquired items are processed more quickly and accurately than those acquired later. Over several decades, the AoA effect has been investigated using neuroscientific, behavioral, corpus and computational…

Studies employing or investigating the metalinguistic judgments of native and nonnative speakers are reviewed. Their results and methodologies are compared to stimulate reliable and informative applications of such judgments in future research. Metalinguistic judgments are found useful in language acquisition studies, given appropriate controls…