Language acquisition is one of the central topics of the broader science of cognition and focuses on the process by which human acquire the capacity to perceive, produce and use words to understand and communicate. Language is the main vehicle by which we know about other people's thoughts, and the two must be intimately related.
Every time we speak we are revealing something about language, so the facts of language structure are easy to come by; these data hint at a system of extraordinary complexity.
Nonetheless, learning a first language is something every child does successfully, in a matter of a few years and without the need for formal lessons. Language acquisition usually refers to first language acquisition, which studies infants' acquisition of their native language, rather than second language acquisition, which deals with acquisition (in both children and adults) of additional languages.
