Cognitive approaches investigate memory and attention processes; sociocultural theories emphasize the role of social interaction and immersion; and linguistic studies examine the innate and learned aspects of language.
Individual factors like age, motivation, and personality also influence SLA, as seen in discussions on the critical period hypothesis and learning strategies.
In addition to acquisition, SLA explores language loss, or second-language attrition, and the impact of formal instruction on learning outcomes.
[5] 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.
Category II Languages include German, Haitian Creole, Indonesian, Malay, and Swahili (approx.
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.
[21] 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.
They have also been used to explain errors in SLA, as the creation of supersets could signal over-generalization, causing acceptance or production of ungrammatical sentences.
[24] Recognizing learners' developmental stages is important as it enables teachers to predict and classify learning errors.
One goal of learnability theory is to figure out which linguistic phenomena are susceptible to fossilization, wherein some L2 learners continue to make errors despite the presence of relevant input.
As such, cognitive theories view second-language acquisition as a special case of more general learning mechanisms in the brain.
This puts them in direct contrast with linguistic theories, which posit that language acquisition uses a unique process different from other types of learning.
[45] A learner's sense of connection to their in-group, as well as to the community of the target language emphasizes the influence of the sociolinguistic setting, as well as social factors within the second-language acquisition process.
A smaller social distance is likely to encourage learners to acquire the second language, as their investment in the learning process is greater.
In Schumann's model, the social factors are most important, but the degree to which learners are comfortable with learning the second language also plays a role.
[51] Language socialization is an approach with the premise that "linguistic and cultural knowledge are constructed through each other",[52] and saw increased attention after the year 2000.
[56] Sociocultural theory has a fundamentally different set of assumptions to approaches to second-language acquisition based on the computational model.
According to Ellis, "It is important to recognize... that this paradigm, despite the label 'sociocultural' does not seek to explain how learners acquire the cultural values of the L2 but rather how knowledge of an L2 is internalized through experiences of a sociocultural nature.
[59] The theory of universal grammar was proposed by Noam Chomsky in the 1950s and has enjoyed considerable popularity in the field of linguistics.
[62] The fact that children are only exposed to positive evidence yet have intuition about which word strings are ungrammatical may also be indicative of universal grammar.
[62] Individual factors, such as language aptitude, age, strategy use, motivation, and personality, play a significant role in second-language acquisition.
For example, the critical period hypothesis explores how age affects language learning ability, while motivation is often categorized into intrinsic and extrinsic types.
Personality traits, such as introversion and extroversion, and the use of effective learning strategies can also influence language acquisition outcomes.
Second-language attrition refers to the loss of proficiency in a language that was previously acquired, often due to a lack of use or exposure.
[46] Factors influencing attrition include the level of initial proficiency, age, social circumstances, and motivation.
This kind of research has a significant overlap with language education, and it is mainly concerned with the effect that instruction has on the learner.
Cited in Ellis 1994 It is generally agreed that pedagogy restricted to teaching grammar rules and vocabulary lists does not give students the ability to use the L2 with accuracy and fluency.
[64][65] As mentioned above, numerous theories have been proposed not only to describe the phenomena of SLA but also to explain them by uncovering the underlying mechanisms.
Despite differing perspectives, these research approaches share a common goal: contributing to the identification of conditions that facilitate effective language acquisition.
These efforts go beyond the limitations of explaining SLA through a single theory, paving the way for a more comprehensive and multilayered understanding.