Understanding how individuals come to master a second language involves a fascinating interplay of natural processes and conscious effort. The field of second-language acquisition (SLA) delves into the developing knowledge and use of a language by children and adults who already know at least one other language. This research is crucial for educational policymakers, helping them set realistic goals for both foreign language courses and programs designed
for minority language children and adults learning a majority language. The distinction between simply "acquiring" a language and "learning" it, as proposed by Stephen Krashen, offers a foundational perspective on this complex journey, highlighting different pathways to proficiency.
Krashen's Monitor Theory: Acquisition Versus Learning
Stephen Krashen, a prominent figure in the 1970s and 1980s, introduced a key distinction within his monitor theory: language acquisition versus language learning. According to Krashen, language acquisition is a natural process, akin to how a child picks up their first language. This process thrives in natural communicative situations where the focus is on meaning and interaction, rather than explicit rules. It's often subconscious and intuitive.
In contrast, language learning is a conscious process. This involves formal instruction, the study of grammatical rules in isolation, and often includes error correction. While not all educators in second language education fully agree with this strict dichotomy, Krashen's framework has significantly influenced the study of SLA. The field examines how a second language is learned or acquired, drawing insights from both linguistic and psychological theories to understand the underlying mechanisms.
Theoretical Foundations of SLA
Second-language acquisition research is deeply rooted in both linguistic and psychological theories. One dominant linguistic theory suggests that the brain contains an innate knowledge device or module specifically designed for language. This perspective posits that humans are biologically predisposed to acquire language, with certain universal grammatical principles already present at birth. This innate capacity helps explain the rapid and seemingly effortless way young children acquire their native tongue.
On the psychological front, many theories propose that general cognitive mechanisms, responsible for various forms of human learning, are also at play in language processing. These theories often emphasize the role of memory, attention, problem-solving, and pattern recognition in the acquisition of a second language. The interplay between these linguistic and psychological perspectives provides a comprehensive view of the cognitive architecture supporting language development.
Diverse Research Areas and Teaching Methods
SLA encompasses a wide array of research areas that have profoundly influenced teaching methodologies. These include studies examining whether findings from first language (L1) acquisition can be transferred to second language (L2) learning, and verbal behavior, which views constructed linguistic stimuli as capable of creating desired speech responses. Other significant areas are morpheme studies, behaviorism, error analysis, and the investigation of stages and order of acquisition. Structuralism, an approach that analyzes how basic language units relate based on common characteristics, also plays a role, as do contrastive analysis, which compares languages for differences and similarities, and inter-language, which describes the L2 learner's language as a dynamic, rule-governed system.
These diverse theories have directly shaped second-language teaching and pedagogy. Many teaching methods stem from specific theoretical frameworks. Common approaches include the grammar-translation method, which emphasizes explicit grammar rules and translation; the direct method, focusing on direct communication in the target language; and the audio-lingual method, heavily influenced by behaviorism and audio-lingual research. Other methods like the Silent Way, suggestopedia, community language learning, and the total physical response method offer varied instructional strategies. The communicative approach, strongly influenced by Krashen's theories, prioritizes meaningful interaction. While some approaches are more popular and considered more effective, most language teachers adopt a mixed style, combining elements from various methods to create a balanced approach that caters to different learning styles and helps students succeed.
The Critical Role of Age in Second Language Proficiency
The age at which a person begins to learn a second language is a defining factor in their eventual proficiency. Linguist Eric Lenneberg, for instance, used "second language" to refer to a language consciously acquired or used after puberty. A common observation is that individuals rarely achieve the same level of fluency and comprehension in their second languages as they do in their first. This phenomenon is closely linked to the critical period hypothesis, which suggests there's an optimal window for language acquisition.
Hyltenstam's research indicated that around the age of six or seven might be a cut-off point for bilinguals to achieve native-like proficiency. After this age, L2 learners could reach near-native-like-ness, but their language, despite few actual errors, would often have enough subtle differences to distinguish them from native speakers. This inability to achieve full native-like proficiency is often correlated with the age of onset (AO) of learning. Later, Hyltenstam and Abrahamsson refined their age cut-offs, arguing that while it generally becomes harder to achieve native-like-ness after childhood, there isn't a single, sharp cut-off point. Emerging knowledge about the brain suggests that puberty might be a crucial period when accents become more ingrained. Before puberty, the brain's chemical processes are more geared towards language and social communication. After puberty, the ability to learn a language without an accent may be rerouted to other brain areas, possibly the frontal lobe for cognitive functions or the neural system for hormone allocation related to reproduction. Krashen, Long, and Scarcella also noted that early exposure to a foreign language leads to better proficiency than learning as an adult. However, adults and older children tend to progress faster through the early stages of syntactic and morphological development, given constant time and exposure. Research by Gauthier and Genesee on internationally adopted children shows that early experiences with one language can affect the ability to acquire a second, often leading to slower and weaker acquisition even during the critical period. While early foreign language education can lead to greater fluency, it might also cause a "weak identification" and a













