People attain varying levels of proficiency in learning a language that is not their mother tongue. While some may sound almost like native speakers, most end up speaking with a recognizable `accent.' What ingredients make up a foreign accent, and to what extent is learning a second language like learning a first one? These are some of the concerns of the field of second language acquisition (SLA). Second Language Phonology, in the series Language Acquisition and Language Disorders, focuses on acquisition of the phonology, the sound system, of a second language.

(Quote from Second Language Phonology by John Archibald John Benjamins 1998.)