This article shows how language processing is intimately tuned to input frequency. Examples are given of frequency effects in the processing of phonology, phonotactics, reading, spelling, lexis, morphosyntax, formulaic language, language comprehension, grammaticality, sentence production, and syntax. The implications of these effects for the representations and developmental sequence of SLA are discussed. Usage-based theories hold that the acquisition of language is exemplar based. It is the piecemeal learning of many thousands of constructions and the frequency-biased abstraction of regularities within them. Determinants of pattern productivity include the power law of practice, cue competition and constraint satisfaction, connectionist learning, and effects of type and token frequency. The regularities of language emerge from experience as categories and prototypical patterns. The typical route of emergence of constructions is from formula, through low-scope pattern, to construction. Frequency plays a large part in explaining sociolinguistic variation and language change. Learners' sensitivity to frequency in all these domains has implications for theories of implicit and explicit learning and their interactions. The review concludes by considering the history of frequency as an explanatory concept in theoretical and applied linguistics, its 40 years of exile, and its necessary reinstatement as a bridging variable that binds the different schools of language acquisition research.

This article presents a study of corrective feedback and learner uptake (i.e., responses to feedback) in four immersion classrooms at the primary level. Transcripts totaling 18.3 hours of classroom interaction taken from 14 subject-matter lessons and 13 French language arts lessons were analyzed using a model developed for the study and comprising the various moves in an error treatment sequence. Results include the frequency and distribution of the six different feedback types used by the four teachers, in addition to the frequency and distribution of different types of learner uptake following each feedback type. The findings indicate an overwhelming tendency for teachers to use recasts in spite of the latter's ineffectiveness at eliciting student-generated repair. Four other feedback types—elicitation, metalinguistic feedback, clarification requests, and repetition—lead to student-generated repair more successfully and are thus able to initiate what the authors characterize as the negotiation of form.

Theoretical claims about the benefits of conversational interaction have been made by Gass (1997), Long (1996), Pica (1994), and others. The Interaction Hypothesis suggests that negotiated interaction can facilitate SLA and that one reason for this could be that, during interaction, learners may receive feedback on their utterances. An interesting issue, which has challenged interactional research, concerns how learners perceive feedback and whether their perceptions affect their subsequent L2 development. The present research addresses the first of these issues–learners' perceptions about interactional feedback. The study, involving 10 learners of English as a second language and 7 learners of Italian as a foreign language, explores learners' perceptions about feedback provided to them through task-based dyadic interaction. Learners received feedback focused on a range of morphosyntactic, lexical, and phonological forms. After completing the tasks, learners watched videotapes of their previous interactions and were asked to introspect about their thoughts at the time the original interactions were in progress. The results showed that learners were relatively accurate in their perceptions about lexical, semantic, and phonological feedback. However, morphosyntactic feedback was generally not perceived as such. Furthermore, the nature as well as the content of the feedback may have affected learners' perceptions.

This study focuses on the impact of different variables on the nature of language performance in the context of task-based instruction. Characteristics of tasks are discussed, and then a framework is offered that can organize the nature of task-based instruction and relevant research. The framework is used to generate predictions regarding the effects of three different tasks (Personal Information Exchange, Narrative, and Decision-Making) and three different implementation conditions for each task (unplanned, planned but without detail, detailed planning) on the variables of fluency, complexity, and accuracy. The study reports strong effects of planning on fluency and clear effects also on complexity, with a linear relationship between degree of planning and degree of complexity. However, a more complex relationship was discovered between planning and accuracy, with the most accurate performance produced by the less detailed planners. In addition, interactions were found between task type and planning conditions, such that the effects of planning were greater with the Narrative and Decision-Making tasks than with the Personal Information Exchange task. The results are discussed in terms of an attentional model of learning and performance and highlight the importance of tradeoff effects between the goals of complexity and accuracy in the context of the use of limited capacity attentional resources. The study contributes to the development of cognitive models of second language performance and addresses a number of pedagogic issues.

This article reviews the second language research on age-related differences, as well as first language work needed to disambiguate some of the findings. Five conclusions are drawn, (a) Both the initial rate of acquisition and the ultimate level of attainment depend in part on the age at which learning begins. (b) There are sensitive periods governing language development, first or second, during which the acquisition of different linguistic abilities is successful and after which it is irregular and incomplete. (c) The age-related loss in ability is cumulative (not a catastrophic one-time event), affecting first one linguistic domain and then another, and is not limited to phonology, (d) The deterioration in some individuals begins as early as age 6—not at puberty as is often claimed. (e) Affective, input, and current cognitive explanations for the reduced ability are inadequate. The capacity for language development is maturationally constrained, and its decline probably reflects a progressive loss of neural plasticity, itself possibly associated with increasing myelination.

A problem facing investigations of implicit and explicit learning is the lack of valid measures of second language implicit and explicit knowledge. This paper attempts to establish operational definitions of these two constructs and reports a psychometric study of a battery of tests designed to provide relatively independent measures of them. These tests were (a) an oral imitation test involving grammatical and ungrammatical sentences, (b) an oral narration test, (c) a timed grammaticality judgment test (GJT), (d) an untimed GJT with the same content, and (e) a metalinguistic knowledge test. Tests (a), (b), and (c) were designed as measures of implicit knowledge, and tests (d) and (e) were designed as measures of explicit knowledge. All of the tests examined 17 English grammatical structures. A principal component factor analysis produced two clear factors. This analysis showed that the scores from tests (a), (b), and (c) loaded on Factor 1, whereas the scores from ungrammatical sentences in test (d) and total scores from test (e) loaded on Factor 2. These two factors are interpreted as corresponding to implicit and explicit knowledge, respectively. A number of secondary analyses to support this interpretation of the construct validity of the tests are also reported.This research was funded by a Marsden Fund grant awarded by the Royal Society of Arts of New Zealand to Rod Ellis and Cathie Elder. Other researchers who contributed to the research are Shawn Loewen, Rosemary Erlam, Satomi Mizutani, and Shuhei Hidaka.The author wishes to thank Nick Ellis, Jim Lantolf, and two anonymous SSLA reviewers. Their constructive comments have helped me to present the theoretical background of the study more convincingly and to remove errors from the results and refine my interpretations of them.

This study was designed to extend previous research on the relationships among intelligibility, perceived comprehensibility, and accentedness. Accent and comprehensibility ratings and transcriptions of accented speech from Cantonese, Japanese, Polish, and Spanish intermediate ESL students were obtained from 26 native English listeners. The listeners were also asked to identify the first language backgrounds of the same talkers and to provide information on their familiarity with the four accents used in this study. When the results of this study were compared with the Munro and Derwing (1995, Language Learning, 45, 73–97) study of learners of high proficiency, speaker proficiency level did not appear to affect the quasi-independent relationships among intelligibility, perceived comprehensibility, and accentedness; however, the relative contributions of grammatical and phonemic errors and goodness of prosody differed somewhat. Ability to identify the speakers' first languages was influenced by familiarity.

Recent research on pragmatic and syntactic development in bilingual 2-year-olds has shown that these children have differentiated language systems. However, it remains to be shown whether their grammars develop autonomously or interdependently from 2 years onward. The present study investigates the potential interference between the grammars of French-English bilingual children, aged 2–3 years. We examined their acquisition of functional categories, specifically the properties of INFL (finiteness and agreement) and negation, as these grammatical properties differ in both adult French and English and child French and English. Our results indicate that the bilingual children show no evidence of transfer, acceleration, or delay in acquisition, and support the hypothesis that their grammars are acquired autonomously. Some implications of these findings for the debate on continuity in the emergence of functional categories are discussed.

To investigate the pedagogical effectiveness of oral corrective feedback (CF) on target language development, we conducted a meta-analysis that focused exclusively on 15 classroom-based studies (N = 827). The analysis was designed to investigate whether CF was effective in classroom settings and, if so, whether its effectiveness varied according to (a) types of CF, (b) types and timing of outcome measures, (c) instructional setting (second vs. foreign language classroom), (d) treatment length, and (e) learners’ age. Results revealed that CF had significant and durable effects on target language development. The effects were larger for prompts than recasts and most apparent in measures that elicit free constructed responses. Whereas instructional setting was not identified as a contributing factor to CF effectiveness, effects of long treatments were larger than those of short-to-medium treatments but not distinguishable from those of brief treatments. A simple regression analysis revealed effects for age, with younger learners benefiting from CF more than older learners.

This article reviews previous studies of the effects of implicit and explicit corrective feedback on SLA, pointing out a number of methodological problems. It then reports on a new study of the effects of these two types of corrective feedback on the acquisition of past tense -ed. In an experimental design (two experimental groups and a control group), low-intermediate learners of second language English completed two communicative tasks during which they received either recasts (implicit feedback) or metalinguistic explanation (explicit feedback) in response to any utterance that contained an error in the target structure. Acquisition was measured by means of an oral imitation test (designed to measure implicit knowledge) and both an untimed grammaticality judgment test and a metalinguistic knowledge test (both designed to measure explicit knowledge). The tests were administered prior to the instruction, 1 day after the instruction, and again 2 weeks later. Statistical comparisons of the learners' performance on the posttests showed a clear advantage for explicit feedback over implicit feedback for both the delayed imitation and grammaticality judgment posttests. Thus, the results indicate that metalinguistic explanation benefited implicit as well as explicit knowledge and point to the importance of including measures of both types of knowledge in experimental studies.This research was funded by a Marsden Fund grant awarded by the Royal Society of Arts of New Zealand. Researchers other than the authors who contributed to the research were Jenefer Philip, Satomi Mizutami, Keiko Sakui, and Thomas Delaney. Thanks go to the editors of this special issue and to two anonymous SSLA reviewers of a draft of the article for their constructive comments.

This study investigates the role of context of learning in second language (L2) acquisition. Participants were 40 native speakers of English studying Spanish for one semester in one of two different learning contexts—a formal classroom at a home university (AH) and a study abroad (SA) setting. The research looks at various indexes of oral performance gains—particularly gains in oral fluency as measured by temporal and hesitation phenomena and gains in oral proficiency based on the Oral Proficiency Interview (OPI). The study also examines the relation these oral gains bore to L2-specific cognitive measures of speed of lexical access (word recognition), efficiency (automaticity) of lexical access, and speed and efficiency of attention control hypothesized to underlie oral performance. The learners also provided estimates of the number of hours they spent in extracurricular language-contact activities. The results show that in some respects learners in the SA context made greater gains, both in terms of temporal and hesitation phenomena and in oral proficiency as measured by the OPI, than learners in the AH context. There were also, however, significant interaction effects and correlational patterns indicating complex relationships between oral proficiency, cognitive abilities, and language contact. The results demonstrate the importance of the dynamic interactions that exist among oral, cognitive, and contextual variables. Such interactions may help explain the enormous individual variation one sees in learning outcomes, and they underscore the importance of studying such variables together rather than in isolation.This research was funded in part by a grant to Barbara F. Freed from the Council on International Educational Exchange, New York, in part by a grant from the Natural Sciences and Engineering Research Council of Canada to Norman Segalowitz, and in part by a grant from the Dean's Office, Faculty of Arts and Science at Concordia University, to Segalowitz. The authors wish to thank Joe Collentine, Manuel Díaz-Campos, and Barbara Lafford, who are members of the research team involved in the larger project of which this study is one part. A special note of thanks is due to Nicole Lazar, who is also a member of the research team, for her invaluable statistical advice. Finally, the authors would like to thank Conchita Bueno, Hazel Casas, Elizabeth Gatbonton, Randall Halter, Guy Lacroix, Anne-Marie Linnen, Magnolia Negrete, Irene O'Brien, Laura Renteria-Díaz, Marlene Taube, and Naomi Yamasaki, who helped during various phases of this project.

The concept of input to the language learner is examined with reference to some current theorizing about language processing and the idea of modular systems of knowledge. The question of what this can tell us about the actions taken by teachers and textbook writers is addressed specifically with regard to manipulating, or “enhancing,” the input ideally so that it will affect learner knowledge and thereby learner behavior. The logic of the argumentation is that, in exposing the learner to the second language, we are engaging a whole battery of different processing mechanisms. Input enhancement research and the conclusions drawn from it have to be set within the context of a modular view of language and language learning.

This study explores the question of whether or not learners can consciously attend to both form and meaning when processing input. An experimental procedure is presented in which three levels of learners in four groups were asked to process information under four different conditions: attention to meaning alone; simultaneous attention to meaning and an important lexical item; simultaneous attention to meaning and a grammatical functor; and simultaneous attention to meaning and a verb form. Results suggest that learners, in particular early stage learners, have great difficulty in attending to both form and content. These results raise important questions for current discussions of the role of consciousness in input processing.

Willingness to communicate (WTC) has been defined as the intention to initiate communication, given a choice. It was hypothesized that orientations toward language learning as well as social support would influence students' WTC in a second language. Grade 9 students of L2 French immersion, living in a relatively unilingual Anglophone community, participated in the study. WTC was measured in each of four skill areas: speaking, writing, reading, and comprehension. Five orientations or reasons for studying an L2 were examined: travel, job related, friendship with Francophones, personal knowledge, and school achievement. Results showed that endorsement of all five orientations for language learning was positively correlated with WTC both inside and outside the classroom. Results also showed that social support, particularly from friends, was associated with higher levels of WTC outside the classroom but played less of a role inside the classroom. The support of friends was also associated with higher orientations for travel and for friendship with Francophones. Results are discussed in terms of an emerging situated model.

This paper considers how implicit and explicit knowledge are dissociable but cooperative. It reviews various psychological and neurobiological processes by which explicit knowledge of form-meaning associations impacts upon implicit language learning. The interface is dynamic: It happens transiently during conscious processing, but the influence upon implicit cognition endures thereafter. The primary conscious involvement in SLA is the explicit learning involved in the initial registration of pattern recognizers for constructions that are then tuned and integrated into the system by implicit learning during subsequent input processing. Neural systems in the prefrontal cortex involved in working memory provide attentional selection, perceptual integration, and the unification of consciousness. Neural systems in the hippocampus then bind these disparate cortical representations into unitary episodic representations. These are the mechanisms by which Schmidt's (1990) noticing helps solve Quine's (1960) problem of referential indeterminacy. Explicit memories can also guide the conscious building of novel linguistic utterances through processes of analogy. Formulas, slot-and-frame patterns, drills, and declarative pedagogical grammar rules all contribute to the conscious creation of utterances whose subsequent usage promotes implicit learning and proceduralization. Flawed output can prompt focused feedback by way of recasts that present learners with psycholinguistic data ready for explicit analysis. Other processes of acquisition from output include differentiation, analysis, and preemption. These processes of conscious construction in working memory underpin relationships between individual differences in working memory capacities and language learning aptitude.Thanks to Rod Ellis for first suggesting that I try to write this and to the staff and students at Department of Applied Language Studies and Linguistics University of Auckland (2003), the TESOL Program Temple University Japan (2003), the Chester Language Development Reading Group, and the LOT winter school (2004) for helping me think it through. I am particularly grateful to Michel Paradis, Michael Swan, Karen Roehr, Anne Feryok, and Tamar Keren-Portnoy for pointing their giant biological cameras of consciousness at a prior draft, and for sharing their awareness with me in kindly and constructive fashion. I have learned a lot from it.

Four teachers and their eight classes of 179 fifth-grade (10–11-year-old) students participated in this quasi-experimental classroom study, which investigated the effects of form-focused instruction (FFI) and corrective feedback on immersion students' ability to accurately assign grammatical gender in French. The FFI treatment, designed to draw attention to selected noun endings that reliably predict grammatical gender and to provide opportunities for practice in associating these endings with gender attribution, was implemented in the context of regular subject-matter instruction by three of the four teachers, each with two classes, for approximately 9 hours during a 5-week period, while the fourth teacher taught the same subject matter without FFI to two comparison classes. Additionally, each of the three FFI teachers implemented a different feedback treatment: recasts, prompts, or no feedback. Analyses of pretest, immediate-posttest, and delayed-posttest results showed a significant increase in the ability of students exposed to FFI to correctly assign grammatical gender. Results of the written tasks in particular, and to a lesser degree the oral tasks, revealed that FFI is more effective when combined with prompts than with recasts or no feedback, as a means of enabling L2 learners to acquire rule-based representations of grammatical gender and to proceduralize their knowledge of these emerging forms.This study was funded by the Social Sciences and Humanities Research Council of Canada (nos. 410-98-0175 and 410-2002-0988). Parts of this study were presented at the annual meeting of the American Association for Applied Linguistics in Salt Lake City on April 7, 2002; the Congress of the Social Sciences and Humanities in Toronto on May 26, 2002; and at the Congress of the International Association for Applied Linguistics in Singapore on December 12, 2002. I am grateful to the participating teachers and their students, to Lucy Fazio for her role as research associate in the data collection, to José Correa for his assistance with the statistical analyses, and to the following research assistants for contributions to various phases of this research: Susan Ballinger, Kristina Eisenhower, Andréanne Gagné, Sophie Beaudoin, Laura-Annie Bouffard, France Bourassa, Sophie Bourgeois, Elisa David, Mélanie Mathieu, Sophie Prince, Andrea Sterzuk, and David Syncox. I gratefully acknowledge Leila Ranta, Iliana Panova, and four anonymous SSLA reviewers for their helpful comments on an earlier version of this paper.

A number of studies on second language (SL) instruction point to the hypothesis that instruction is effective, but determining the effect experimentally has been problematic. Overall, three difficulties with previous attempts to demonstrate a causal relationship between SL instruction and second language acquisition can be identified: (a) inappropriate or inadequate research design, (b) failure to operationalize or even to describe the instructional treatment, and (c) choice of SL assessment measures. This article presents the findings of a recent empirical study which (a) show that SL instruction is effective; (b) show that attention to form, either via detailed analysis of structure or highlighting of target language (TL) structures in context, promotes acquisition of interlanguage (IL) grammar, but that only the latter comes hand-in-hand with comprehension of input; and (c) replicate earlier findings suggesting an important role for markedness theory in instructed IL development.

This study examines aspects of communicative classroom discourse that may affect the potential of recasts to be noticed as negative evidence by young second language learners. The database comprises transcripts of over 18 hours of interaction recorded during 27 lessons in 4 immersion classrooms at the primary level. The 377 recasts in the database have been classified according to their pragmatic functions in classroom discourse and then compared to the teachers' even more frequent use of noncorrective repetition. Findings reveal that recasts and noncorrective repetition fulfill identical functions distributed in equal proportions and, furthermore, that teachers frequently use positive feedback to express approval of the content of learners' messages, irrespective of well-formedness, to accompany, also in equal proportions, recasts, noncorrective repetition, and even topic-continuation moves following errors. The findings suggest that, from the perspective of both learners and teachers, the corrective reformulations entailed in recasts may easily be overridden by their functional properties in meaning-oriented classrooms.

This study examines the relationship between different types of conversational interaction and SLA. Long's (1996) updated version of the interactionist hypothesis claims that implicit negative feedback, which can be obtained through negotiated interaction, facilitates SLA. Similar claims for the benefits of negotiation have been made by Pica (1994) and Gass (1997). Some support for the interaction hypothesis has been provided by studies that have explored the effects of interaction on production (Gass & Varonis, 1994), on lexical acquisition (Ellis, Tanaka, & Yamazaki, 1994), on the short-term outcomes of pushed output (see Swain, 1995), and for specific interactional features such as recasts (Long, Inagaki, & Ortega, 1998; Mackey & Philp, 1998). However, other studies have not found effects for interaction on grammatical development (Loschky, 1994). The central question addressed by the current study was: Can conversational interaction facilitate second language development? The study employed a pretest-posttest design. Adult ESL learners (N = 34) of varying L1 backgrounds were divided into four experimental groups and one control group. They took part in task-based interaction. Research questions focused on the developmental outcomes of taking part in various types of interaction. Active participation in interaction and the developmental level of the learner were considered. Results of this study support claims concerning a link between interaction and grammatical development and highlight the importance of active participation in the interaction.

This paper provides an overview of sequencing in SLA. It contends that much of language acquisition is in fact sequence learning (for vocabulary, the phonological units of language and their phonotactic sequences: for discourse, the lexical units of language and their sequences in clauses and collocations). It argues that the resultant long-term knowledge base of language sequences serves as the database for the acquisition of language grammar. It next demonstrates that SLA of lexis, idiom, collocation, and grammar are all determined by individual differences in learners' ability to remember simple verbal strings in order. It outlines how interactions between short-term and long-term phonological memory systems allow chunking and the tuning of language systems better to represent structural information for particular languages. It proposes mechanisms for the analysis of sequence information that result in knowledge of underlying grammar. Finally, it considers the relations between this empiricist approach and that of generative grammar.