Cognitive Abilities Test (CAT4) Practice Exam 2025 - Free CAT4 Practice Questions and Study Guide

Second language acquisition refers to the process through which an individual learns a language other than their native language. This is particularly relevant for adults who seek to gain proficiency in a new language, typically distinct from their first language acquired during childhood. The process involves various components, including understanding grammar, vocabulary, pronunciation, and cultural nuances.

In the context of this question, first language acquisition pertains to the natural and instinctive way in which children learn their native language, an experience that is fundamentally different from learning a second language in adulthood. Vocabulary development is more focused on the expansion of one's word knowledge within any language, while language proficiency describes the level of skill that someone has achieved in any language, rather than the process of learning itself. Thus, second language acquisition precisely captures the focus on adults learning a new language, making it the correct answer.