The Role of Age and Instruction in Children's Learning of Vocabulary and Grammar

Abstract It is generally assumed that children and adults learn language through fundamentally different mechanisms: Children predominantly rely on implicit learning, and adults utilize more explicit strategies (Lichtman, 2016). However, little is known about when and how learners begin to benefit from explicit instruction over the course of language development. Addressing this gap, the present study responds to DeKeyser's (2012, 2013) call to investigate age–treatment interactions (ATIs) under highly controlled experimental conditions. Using a cross‐situational learning (CSL) paradigm, we trained 150 learners aged 8 to 13 to acquire both vocabulary and grammar in a complex artificial language under two instructional conditions: implicit and explicit. Results indicated that, in this task, 12‐to‐13‐year‐old children showed clearer benefits from explicit instruction than younger children, particularly for grammatical information related to word order. These findings shed light on the developmental stage at which explicit instruction may become beneficial for children's nonnative language (L2) learning.