Main Second Language Acquisition Theories: from Structuralism to Complexity

This article presents a literature review of the main second language acquisition (SLA) theories. It first deals with the very beginning of SLA studies in the middle of the 20 th century, focusing on the studies of Fries and Lado, and then moves on to describe some of the theoretical proposals over the past four decades. Ten theories are briefly described: the structural or behaviorist approach, the pidginization hypothesis or acculturation theory, the identity approach, the input or comprehension hypothesis, the interaction hypothesis, the output hypothesis, the universal grammar theory, the sociocultural theory, the connectionist theory, and the complex systems framework. Key-words: Second language acquisition; Language teaching; Complexity. Research on additional language teaching dates back to the middle of the twentieth century. Since then, several attempts have been made to explain how languages are learned. The several theories focus on different aspects of the phenomenon with emphasis on either the mental or social aspects of learning processes. Revista Contexturas, n. 23, p. 112 124, 2014. ISSN: 0104-7485 113 The very beginning The first works on SLA are those by Charles Fries and his student Robert Lado. Fries (1945) emphasized the importance of contrasting “patterning of the sounds of two languages” (p.15). He claimed that This determining of the distinctive sounds that differ is only the first step (although an important one) in the scientific comparison of the language to be learned with the native language of the learner. Each language has not only its own set of distinctive sound features; it also has only a limited number of characteristic sequences of consonants and vowels which make up the structural pattern of the syllables and