Second-language acquisition
Second-language acquisition, second-language learning or L2 acquisition, is the process of learning a language other than one's native language. SLA research examines how learners develop their knowledge of second language.
SLA research spans cognitive, social, and linguistic perspectives:
- Cognitive approaches investigate memory and attention processes.
- Sociocultural theories emphasize the role of social interaction and immersion
- Linguistic studies examine the innate and learned aspects of language.
Definitions
Second language refers to any language learned in addition to a person's first language; although the concept is called second-language acquisition, it can also incorporate the learning of third, fourth, or subsequent languages. Second-language acquisition refers to what learners do; it does not refer to practices in language teaching, although teaching can affect acquisition. The term acquisition was originally used to emphasize the non-conscious nature of the learning process, but in recent years learning and acquisition have become largely synonymous.SLA can incorporate heritage language learning, but it does not usually incorporate bilingualism. Most SLA researchers see bilingualism as being the result of learning a language, not the process itself, and see the term as referring to native-like fluency. Writers in fields such as education and psychology, however, often use bilingualism loosely to refer to all forms of multilingualism. SLA is also not to be contrasted with the acquisition of a foreign language; rather, the learning of second languages and the learning of foreign languages involve the same fundamental processes in different situations.
Research background
The academic discipline of second-language acquisition is a sub-discipline of applied linguistics. It is broad-based and relatively new. As well as the various branches of linguistics, second-language acquisition is also closely related to psychology and education. To separate the academic discipline from the learning process itself, the terms second-language acquisition research, second-language studies, and second-language acquisition studies are also used.SLA research began as an interdisciplinary field; because of this, it is difficult to identify a precise starting date. However, two papers in particular are seen as instrumental to the development of the modern study of SLA: Pit Corder's 1967 essay The Significance of Learners' Errors and Larry Selinker's 1972 article Interlanguage. The field saw a great deal of development in the following decades. Since the 1980s, SLA has been studied from a variety of disciplinary perspectives, and theoretical perspectives. In the early 2000s, some research suggested an equivalence between the acquisition of human languages and that of computer languages by children in the 5 to 11-year age window, though this has not been widely accepted amongst educators. Significant approaches in the field today are systemic functional linguistics, sociocultural theory, cognitive linguistics, Noam Chomsky's universal grammar, skill acquisition theory and connectionism.
There has been much debate about exactly how language is learned and many issues are still unresolved. There are many theories of second-language acquisition, but none are accepted as a complete explanation by all SLA researchers. Due to the interdisciplinary nature of the field of SLA, this is not expected to happen in the foreseeable future. Although attempts have been made to provide a more unified account that tries to bridge first language acquisition and second language learning research.
Language difficulty and learning time
The time taken to reach a high level of proficiency can vary depending on the language learned. In the case of native English speakers, some estimates were provided by the Foreign Service Institute of the U.S. Department of State—which compiled approximate learning expectations for several languages for their professional staff. Category I Languages include Italian and Swedish and French. Category II Languages include German, Haitian Creole, Indonesian, Malay, and Swahili. Category III Languages include many languages, such as Finnish, Polish, Russian, Tagalog, Vietnamese, and many others.Determining a language's difficulty can depend on a few factors like grammar and pronunciation. For instance, Norwegian is one of the easiest languages to learn for English speakers because its vocabulary shares many cognates and has a sentence structure similar to English.
Of the 63 languages analyzed, the five most difficult languages to reach proficiency in speaking and reading, requiring 88 weeks, are Arabic, Cantonese, Mandarin, Japanese, and Korean. The Foreign Service Institute and the National Virtual Translation Center both note that Japanese is typically more difficult to learn than other languages in this group.
There are other rankings of language difficulty as the one by The British Foreign Office Diplomatic Service Language Centre which lists the difficult languages in Class I
; the easier languages are in Class V.
Comparisons with first-language acquisition
Adults who learn a second language differ from children learning their first language in at least three ways: children are still developing their brains whereas adults have mature minds, and adults have at least a first language that orients their thinking and speaking. Although some adult second-language learners reach very high levels of proficiency, pronunciation tends to be non-native. This lack of native pronunciation in adult learners is explained by the critical period hypothesis. When a learner's speech plateaus, it is known as fossilization.Also, when people learn a second language, the way they speak their first language changes in subtle ways. These changes can be with any aspect of language, from pronunciation and syntax to the gestures the learner makes and the language features they tend to notice. For example, French speakers who spoke English as a second language pronounced the /t/ sound in French differently from monolingual French speakers. This kind of change in pronunciation has been found even at the onset of second-language acquisition; for example, English speakers pronounced the English /p t k/ sounds, as well as English vowels, differently after they began to learn Korean. These effects of the second language on the first led Vivian Cook to propose the idea of multi-competence, which sees the different languages a person speaks not as separate systems, but as related systems in their mind. A 2025 study found that adult learners can attune to the prosody of a new language after brief exposure, but that concurrent exposure to orthography—especially deep or unfamiliar scripts—hampers this ability. This suggests that difficulties with second-language prosody may be influenced by learning conditions, not just age-related factors.
Learner language
Originally, attempts to describe learner language were based on comparing different languages or analyzing learners' errors. However, these approaches could not fully predict all the errors learners make during the process of acquiring a second language. To address this limitation and explain learners’ systematic errors, the concept of interlanguage was introduced. Interlanguage refers to the linguistic system that emerges in the minds of second language learners. It is not considered a defective version of the target language riddled with random errors, nor is it purely a result of errors transferred from the learner’s first language. Instead, it is viewed as a language in its own right, with its own systematic rules. Most aspects of language—syntax, phonology, lexicon, and pragmatics—can be analyzed from the perspective of interlanguage. For more detailed information, please refer to the main articles on Interlanguage.Sequences in the acquisition of English inflectional morphology
In the 1970s, several studies investigated the order in which learners acquired different grammatical structures. These studies showed that there was little change in this order among learners with different first languages. Furthermore, it showed that the order was the same for adults and children and that it did not even change if the learner had language lessons. This supported the idea that there were factors other than language transfer involved in learning second languages and was a strong confirmation of the concept of interlanguage.However, the studies did not find that the orders were the same. Although there were remarkable similarities in the order in which all learners learned second-language grammar, there were still some differences between individuals and learners with different first languages. It is also difficult to tell when exactly a grammatical structure has been learned, as learners may use structures correctly in some situations but not in others. Thus it is more accurate to speak of sequences of acquisition, in which specific grammatical features in a language are acquired before or after certain others but the overall order of acquisition is less rigid.
Recent studies have shown that universality and individuality coexist in the order of grammatical item acquisition. For example, items such as articles, tense, and the progressive aspect are particularly challenging for learners whose native languages, like Japanese and Korean, do not explicitly express these features. On the other hand, items like the third-person singular -s tend to be less influenced by the learner's native language. In contrast, articles and the progressive -ing have been confirmed to be strongly affected by the learners' native language. For more detailed information, please refer to the main articles on Order of acquisition.