It is common knowledge that a foreign accent is typical of postpubescent language learners. Comedians who mimic speakers of foreign languages always select the foreign accent as an object of their humor; they less frequently target syntax or the lexicon. With so much attention paid to phonology in everyday treatments of foreign language speakers, it is surprising how little attention has been paid to this area of the grammar within the second language acquisition literature.

Learning a second language phonology is more complex than generally thought. Much pedagogical material focuses on the learning of segments; most learners, as a result, are concerned with the accurate production and reception of segments. However, it is clear that learning a second language (L2) phonology embraces considerably more than achieving accurate segment production: One must also gain knowledge of allowable and disallowable sequences, phonetic detail of segment combinations, meaning-bearing and nonmeaning-bearing prosodic elements, and so forth.

The chapters in this section approach phonology from different perspectives. Ard takes a global view of L2 phonology, presenting a model for L2 phonological development. Mairs, on the other hand, provides an in-depth investigation of one aspect of L2 phonological acquisition – stress assignment.

Ard's chapter points out that there is no existing model of L2 phonology. He claims that the problem is not with the output side of phonology; many studies have addressed and systematized the actual pronunciations and perceptions of second language learners.