Typical language development

Acquiring language is a major developmental feat that all typical, healthy children achieve during the first years of their lives. The ease and speed with which they acquire their native language(s) has puzzled parents, scholars, and the general public alike. The last five decades have brought about a spectacular increase in our knowledge of how young infants acquire their mother tongues. Sophisticated behavioral, corpus-based, and brain imaging techniques have been developed to query young learners' journey into language. This chapter summarizes what we currently know of typical language development during the first years of life. It starts out by reviewing the existing theoretical accounts of language development. It then presents the most important empirical findings about speech perception and language acquisition grouped by different subdomains, such as newborns' speech perception abilities, phoneme perception, word learning, and the early acquisition of grammar, focusing mainly on the first 3 years of life, an age by which the major milestones of language development are typically accomplished. Differences between monolingual and multilingual development are also discussed.