De Bot Research Articles

A “linguistic approach” to the idiosyncratic nature of second language acquisition: Monosyllabic place-holders and morpheme orders

It is important that there be different approaches to Second Language Acquisition (SLA) research, some of which will be contrasting and some complementary. In the former case, the contrast may lead to a review of assumptions which will result in mutual or unilateral enrichment. In the latter case, it is obvious that we are to aim at achieving a comprehensive view of SLA. In this respect, in the paper by De Bot, Lowie and Werspoor, “A Dynamic Systems Theory approach to second language acquisition”, while there is some room for a complementary approach, what stands out is a view contrasting with the Universal Grammar (UG) view. For instance, the authors mention Larsen-Freeman (2002) – one of the pioneers of the application of the Dynamic Systems Theory (DST) to SLA research – as suggesting that a UG approach and the DST may be two complementary perspectives, but they emphasize that Larsen-Freeman is very much on the side of emergentist (non-nativist) views. Furthermore, they make it clear that leading DST researchers “leave little room for nativist ideas on language acquisition” (p. 10). However, while the authors put the DST forward as the approach that can avoid the shortcomings of a partial model which only deals with cognitive aspects of language development, they fail to recognize that the cognitive approach has never claimed to have all the answers to the SLA phenomenon, and neither do they. In fact, what we would like to show in this commentary is that the “linguistic” or “cognitive” approach to SLA research can account (and even explain) why native (L1) and non-native (L2) grammars are different. In order to show this, we will address two issues that De Bot, Lowie and Werspoor use as evidence against the nativist approach: Newport's (1991) “less is more” hypothesis and the authors' review of the “variation and morpheme order studies”. We will be discussing their views from the UG approach perspective which we refer to as the “Linguistic Approach” and which has its foundation in the nativist Chomskian tradition which, in the case of SLA research, is represented in volumes such as Liceras (1986), White (1989, 2003), Strozer (1994) and Hawkins (2001), among many others.

DST vs. UG: Can DST account for purely linguistic phenomena?

The article “A Dynamic Systems Theory approach to second language acquisition” by De Bot, Lowie and Verspoor discusses Dynamic Systems Theory (DST), and in particular the benefits of studying second language acquisition (SLA) within the DST framework. The article explains the main characteristics of DST, and goes on to show how various aspects of SLA can be treated from a DST perspective. In particular, the article proposes that the DST framework allows an investigation of how various social and cognitive aspects of SLA interact.

Dynamic systems in second language learning: Some general methodological reflections

In this rich and provocative article, De Bot, Lowie and Verspoor provide a clear and informative description of the central tenets of dynamic systems theory and apply this to a number of theoretical and empirical issues in second language acquisition. The authors see dynamic systems theory as a promise for the future, an overarching theory in second language acquisition that takes into account the interconnectedness that is so characteristic of complex, developing systems, including the cognitive and social factors that help shape the process of second language acquisition. Having pioneered in dynamic systems for quite some time now (see Van Geert and Steenbeek, 2005, for a recent overview), I cannot be but supportive of their vision and their hope that this particular approach will lead to a fuller understanding of second language acquisition that is not only of theoretical but also of applied importance. However, the authors' remark about “some unresolved issues” in Dynamic Systems Theory may be somewhat over-optimistic. Nevertheless, I consider the dynamic systems approach as the quintessential future approach to human action, cognition and behavior, including language. All these phenomena are about change, about process in time. And this is exactly what dynamic systems approaches provide: an explicit model of change of some phenomenon of interest.

Variation and dynamic systems in SLA

In their paper De Bot, Lowie and Verspoor (henceforth DBL&V) attempt to recast SLA research from a non-modular and psychometric position that is based on the assumption that “all variables are interrelated and therefore changes in one variable will have an impact on all other variables that are part of the system” (p. 8). In such grand endeavour their paper naturally raises a large number of issues in SLA research.

The Handbook of Applied Linguistics (review)

Reviewed by: The handbook of applied linguistics ed. by Alan Davies and Catherine Elder Bernard Spolsky The handbook of applied linguistics. Ed. by Alan Davies and Catherine Elder. Malden, MA: Blackwell, 2003. Pp. 888. ISBN 1405138092. $49.95. In the last few decades, the field of applied linguistics has flourished so that it now has national and international associations, university departments that include the term in their titles, a growing collection of academic and professional journals, and a mounting number of books, encyclopedias, and handbooks. Most major universities now offer one or more courses in applied linguistics at undergraduate and graduate levels, and a handbook like the one under review will certainly provide instructors in such a course with a good sketch of the field and of its current concerns. Alan Davies is especially qualified to edit a volume such as this, having taught since 1965 at Edinburgh University, one of the pioneering institutions in the field of applied linguistics. The editors organize the thirty-two topical chapters into two clusters, the first representing an approach characterized as ‘linguistics applied’ (which assumes that language problems can be solved using concepts from linguistics) and ‘applied linguistics’ (which accepts the centrality of linguistics but assumes the necessity of input from other disciplines). There are, conveniently, sixteen chapters in each part. After the editors set out their underlying assumptions and summarize the first part, Anthony J. Liddicoat and Timothy J. Curnow in the first chapter provide a theory-neutral account of language descriptions, though space limitations prevent their setting out details of the vast amount of research in linguistics and languages that one would want to apply. This is followed by a brief account of lexicography by Alan Kirkness, emphasizing the range of learners’ dictionaries. Ch. 3, by David Birdsong, provides a useful discussion of the notion of ultimate attainment in second language learning, arguing (against those who take a strong position in favor of the critical period) that second language learners can be as successful as first language learners. There is, it should be noted, a complete handbook devoted to the topic of second language acquisition (Doughty & Long 2003). Michael Stubbs describes how the computer, by furnishing easy access to larger and larger collections of language texts, has engendered increasing studies of language corpora. The following two chapters provide overviews of discourse analysis (Hugh Trappes-Lomax)—there is a Blackwell handbook for this too (Schiffrin et al. 2003)—and of British Sign Language as a minority language (Rachel Sutton-Spence and Bencie Woll). Howard Giles and Andrew C. Billings review forty years of studies of language attitudes, concentrating especially on the multiple-guise technique. Although often considered social psychology, it still fits the editors’ definition of linguistics applied. Monika S. Schmid and Kees de Bot summarize studies of the attrition of the first language. Claire Kramsch draws on a number of disciplines besides linguistics and on crossdisciplinary fields to present her thinking about linguistic relativity. Rod Gardner traces the field of conversational analysis since the [End Page 202] pioneering work of Schegloff nearly forty years ago. John Gibbons discusses legal language, problems of courtroom interpretation, the nature of linguistic evidence, and the issue of linguistic identification or profiling: these are areas that have burgeoned rapidly even in the short time since the paper was written. Susan Ehrlich presents a brief review of the extensive research on language and gender (for more details, one might try another Blackwell handbook, Holmes & Meyerhoff 2003). John McRae and Urszula Clark append poems by William Wordsworth and Langston Hughes to a summary of definitions and approaches to stylistics. Tackling an issue that has recently become fashionable among applied linguists, John E. Joseph discusses language and politics, dealing with correctness, Marxism, structuralism, and language choice. Kingsley Bolton presents various approaches to the study of World Englishes, providing a thought-provoking examination of the political aspect of applied linguistics. Concluding this section, Kanavillil R...

Modeling the control of phonological encoding in bilingual speakers

Phonological encoding is the process by which speakers retrieve phonemic segments for morphemes from memory and use the segments to assemble phonological representations of words to be spoken. When conversing in one language, bilingual speakers have to resist the temptation of encoding word forms using the phonological rules and representations of the other language. We argue that the activation of phonological representations is not restricted to the target language and that the phonological representations of languages are not separate. We advance a view of bilingual control in which condition-action rules determine what is done with the activated phonological information depending on the target language. This view is computationally implemented in the WEAVER++ model. We present WEAVER++ simulations of the cognate facilitation effect (Costa, Caramazza and Sebastián-Gallés, 2000) and the between-language phonological facilitation effect of spoken distractor words in object naming (Hermans, Bongaerts, de Bot and Schreuder, 1998).

Author's reply to de Bot et al.

Author's reply to de Bot et al.

The components of bilingual proficiency

Research reports from three areas of investigation (exceptional bilingualism, early differentiation in childhood bilingualism, and language mixing) are discussed with the purpose of exploring the applicability of the concept of modularity. Components of bilingual proficiency can be studied from a modular perspective along two dimensions: (1) autonomy and interaction between representations of the bilingual's two languages, (2) degrees and kinds of autonomy of Conceptual Structures from the linguistic structures of both languages, and how these domains interact. A model of bilingual proficiency is proposed based on an adaptation of Jackendoff's Tripartite Parallel Architecture (TPA). Jackendoff's (2002) assessment of Levelt's (1999) theory of speech processing represents an important attempt to promote an interdisciplinary exchange around a conception of modularity that is more in line with recent psycholinguistic research. De Bot's (2000 /1992) bilingual adaptation of Levelt's model is discussed as a key contribution to a developing convergence, taking advantage of the special opportunities that the study of bilingualism offers to the discussion. While a number of points of divergence remain between the Levelt and de Bot models on the one hand, and Jackendoff's TPA and the proposed Bilingual TPA on the other, it is not clear if these differences are of substance or rather the result of analyzing bilingual proficiency from alternate vantage points. The proposal offered for discussion in this paper is inclined toward the latter.

Another look at cross-language competition in bilingual speech production: Lexical and phonological factors

How does lexical selection function in highly-proficient bilingual speakers? What is the role of the non-response language during the course of lexicalization? Evidence of cross-language interference was obtained by Hermans, Bongaerts, De Bot and Schreuder (1998) using the picture-word interference paradigm: participants took longer to name the picture when it appeared with a word phonologically related to the target's translation than when it was accompanied by a control (phono-translation interference). Here we report two picture-word interference experiments that explored whether the same pattern of interference is present for highly-proficient bilinguals producing speech in L2. The results of the two experiments partially replicate those of Hermans et al. (1998), revealing the reliability of the phono-translation effect. We discuss some possible loci of this effect during the lexicalization process, and its implications for models of bilinguals speech production.

The Bilingualism Reader (review)

Reviewed by: The bilingualism reader ed. by Li Wei Susan Meredith Burt The bilingualism reader. Ed. by Li Wei. London & New York: Routledge, 2000. Pp. xv, 541. $29.99. The editor’s goal for this volume is to present ‘a selection of the most important research papers on bilingualism’ (ix) and to make them available to students. The papers, with original publication dates ranging from 1959 to 1997, give an overview of how the field of bilingualism has developed and acquaint readers with current issues. Eighteen chapters are divided among three major sections, with two subdivisions each. Two introductory articles, the editor’s ‘Dimensions of Bilingualism’ (3–25) and William F. Mackey’s ‘The description of bilingualism’ (26–54), orient readers to the rest of the volume. Part 1 covers the sociolinguistic issues of language [End Page 806] choice and bilingual interaction. Classic articles such as Charles Ferguson’s ‘Diglossia’ (65–80), Joshua Fishman’s ‘Bilingualism with and without diglossia; Diglossia with and without bilingualism’ (81–88) and ‘Who speaks what language to whom and when?’ (89–106) introduce basic notions such as ‘diglossia’ and ‘domain’. A variety of sociolinguistic approaches to bilingual interaction are illustrated by four subsequent articles. Jan-Petter Blom and John J. Gumperz’s ‘Social meaning in linguistic structure: Code-switching in Norway’ (111–36) introduces situational and metaphorical codeswitching. An explicitly sociopragmatic approach to code choice is explained in Carol Myers-Scotton’s ‘Codeswitching as indexical of social negotiations’ (137–65), while J. C. Peter Auer provides ‘A conversation analytic approach to code-switching and transfer’ (166–87) in his discussion of Italian-speaking children in Germany. Social network analysis informs the approach of Li Wei, Lesley Milroy, and Pong Sin Ching in ‘A two-step sociolinguistic analysis of code-switching and language choice: The example of a bilingual Chinese community in Britain’ (188–209). Part 2 first focuses on the issue of grammatical constraints in codeswitching. Shana Poplack’s ‘Sometimes I’ll start a sentence in Spanish y termino en español’ (221–56) proposes the free morpheme constraint and the equivalence constraint. Michael Clyne (‘Constraints on code-switching: How universal are they?’, 257–80) questions these and other constraints on the basis of German-English and Dutch-English data. Data from numerous pairs of languages support the matrix language frame model of Carol Myers-Scotton and Janice Jake (‘Matching lemmas in a bilingual language competence and production model’, 281–320), in which congruence (or a lack of it) between languages at conceptual, functional, or positional levels can explain the varieties of intrasentential codeswitching. In the second part of Part 2, Fred Genesee (‘Early bilingual language development: One language or two?’, 327–43) and Juergen M. Meisel (‘Early differentiation of languages in bilingual children’, 344–69) bring evidence against the hypothesis that bilingual children initially have only one grammatical system. Similarly, two articles in Part 3 demonstrate the lack of evidence for language-specific lateralization in bilinguals: Loraine K. Obler, Robert J. Zatorre, Linda Galloway, and Jyotsna Vaid (‘Cerebral lateralization in bilinguals: Methodological issues’, 381–93) caution about the numerous parameters involved, while Michel Paradis (‘Language lateralization in bilinguals: Enough already!’, 394–401) reviews the lack of evidence. Three final papers propose models of bilingual speech processing. David W. Green (‘Control, activation and resource’, 407–19) proposes a model for bilingual functioning that accounts for data from both normal and brain-damaged speakers. Kees De Bot (‘A bilingual production model’, 420–42) adapts Willem Levelt’s monolingual model for bilingual speakers. François Grosjean (‘Processing mixed language: Issues, findings, models’, 443–69) reviews the pitfalls of psycholinguistic research in this area. Each major section is followed by study questions, research activities, and suggestions for further reading. The end of the volume features a short discussion by W on the effects of researcher identity and bias; a resource list of reference works, textbooks, and journals...

THE BILINGUALISM READER. Li Wei (Ed.). London: Routledge, 2000. Pp. xv + 541. £18.99 paper.

This volume consists of a collection of 18 chapters of previously published articles, mostly classic works on bilingualism (all but five were published before 1990). The majority of the authors are very well known and well respected scholars in the field: Auer, Blom, Ching, Clyne, de Bot, Ferguson, Fishman, Galloway, Genesee, Green, Grosjean, Gumperz, Jake, Mackey, Meisel, Milroy, Myers-Scotten, Obler, Paradis, Poplack, Vaid, Wei, and Zatorre. Wei's motivation for this reader is that it serve the dual purpose of compiling many of the important articles on bilingualism, which in many parts of the world are unavailable because of inadequate library facilities, and encourage researchers to read the original works rather than commentaries on them. As Wei put it, “I am nevertheless concerned that a new generation of ‘scholars' might be emerging out of a ‘hear-say' tradition” (p. ix).

The Impact of Exploitation on Freshwater Mussels (Bivalvia: Hyriidae) in the Tocantins River, Brazil

Freshwater mussels in the Tocantins River are exploited for their shells to make buttons. Data were collected on mussel density, size frequency distribution, habitat and exploitation level at five sites. The most abundant species is Paxyodon syrmatophorus (Meuschen, 1781) and is preferred by fishermen. Mean harvested shell size is larger than that of randomly sampled mussels for all species. No individuals below 30 mm were found among harvested shells. Exploitation level varied among sites. Mussel density and mean shell size were correlated with exploitation level and with some habitat parameters. The results are discussed in relation to strategies for the management of existing stocks. Bivalves de água doce no rio Tocantins são explorados pelas conchas para a confecção de botões. Em cinco sítios, dados foram obtidos sobre densidade, distribuição em tamanho, hábitat e nível de exploração dos moluscos. O bivalve mais abundante e mais preferido pelos coletadores de conchas foi Paxyodon syrmatophorus (Meuschen, 1781). O tamanho em média das conchas coletadas é maior do que o das conchas amostradas aleatóriamente. Só indivíduos acima de 30 mm em tamanho foram encontrados entre conchas coletadas. O nível de exploração variou entre sítios. Densidade e tamanho média das conchas foram relacionados com o nível de exploração e alguns parâmetros de hábitat. Os resultados são discutidos em relação às estratégias de manejo dos estoques já existentes.

A psycholinguistic interpretation of codeswitching: Evidence from fluent Greek-English bilingual adults

Recent research on psycholinguistic aspects of bilingual production has been aimed at general modeling issues (De Bot & Schreuder, 1993), control of processing (Green, 1993), and the formulation of output (Azuma, 1993; Myers-Scotton, 1993). In the latter approach, codeswitching, henceforth `CS' has been an important source of evidence, on the concept of a “base” language, and the claim that closed class words do not codeswitch. The present study provides further evidence on these and related issues drawn from a previously untapped source of bilingual performance involving GreekEnglish conversational data. We propose that a useful line of research is opened up by the assumption that CS is revealing of linguistic units that are planned in real time during the opened up by the assumption that CS is revealing of linguistic units that are planned in real time during the production process. We present a methodology for the systematic observation of CS distribution in our corpus, based on a range of defined units of discourse organization including the turn and different types of units within the turn, down to the level of the word. CS is found not to occur within word unit boundaries. Findings suggest that the turn and immediate subturn unit boundaries are important loci for CS; that a variety of units beside the clause (Ford, 1982) and the verb phrase are operating in the planning process; that CS occurs preferentially before adjuncts, and before head words in constituents, especially nouns; and that closed class words are involved in CS. We conclude that planning for bilingual language production involves a range of different, and quite small, units, and that both languages contribute to the on-line building of utterance frames.

Negotiation of Form, Recasts, and Explicit Correction in Relation to Error Types and Learner Repair in Immersion Classrooms

This study investigated specific patterns of a reactive approach to form‐focused instruction: namely, corrective feedback and its relationship to error types and immediate learner repair. The database is drawn from transcripts of audio recordings made in four French immersion class‐rooms at the elementary level, totaling 18.3 hours and including 921 error sequences. The 921 learner errors were coded as grammatical, lexical, or phonological, or as unsolicited uses of L1. Corrective feedback moves were coded as explicit correction, recast, or negotiation of form (i.e., elicitation, metalinguistic clues, clarification requests, or repetition of error).In contrast with previous studies of error treatment in L2 classrooms, which showed that teachers' use of corrective feedback was relatively unsystematic, this study revealed a certain degree of systematicity in the teachers' treatment of specific types of oral errors. First, the proportion of error types receiving corrective feedback from the teachers reflected the rate at which these various error types actually occurred. Second, the teachers tended to provide feedback on phonological and lexical errors with a certain amount of consistency (at rates of 70% and 80%, respectively); grammatical errors received corrective feedback at a lower rate, but accounted for the highest number of corrective feedback moves in the database nonetheless. Third, the teachers tended to select feedback types in accordance with error types: namely, recasts after grammatical and phonological errors and negotiation of form after lexical errors.Overall, the negotiation of form proved to be more effective at leading to immediate repair than recasts or explicit correction, particularly in the case of lexical errors and also in the case of grammatical errors and unsolicited uses of L1, but not in the case of phonological errors; the latter clearly benefit from recasts. This pattern suggests (a) that the teachers were on the right track in their decisions to recast phonological errors and to negotiate lexical errors and (b) that perhaps teachers could draw more frequently on the negotiation of form in response to grammatical errors, because almost two thirds of all grammatical repairs resulted from this type of feedback. A preference for providing feedback in this way is supported by de Bot's (1996) argument that language learners are likely to benefit more from being “pushed” (Swain, 1995) to retrieve target language forms than from merely hearing the forms in the input, because the retrieval and subsequent production stimulate the development of connections in memory.

TOWARD A LEXICAL PROCESSING MODEL FOR THE STUDY OF SECOND LANGUAGE VOCABULARY ACQUISITION

A major requirement for theory development in L2 vocabulary acquisition is an adequate model of L2 lexical organization and processing. At present, there is no widely accepted model of this kind, but recent research has demonstrated the potential usefulness of Levelt's (1989, 1993) L1 speech processing model (de Bot & Schreuder, 1993; Green, 1993; Poulisse, 1993). This paper explores the relevance of the model as adapted for L2 lexical processing of written texts, with particular attention to its mental lexicon components (concepts, lemmas, and lexemes) and organization. The model is first discussed in terms of its relevance to L2 lexical access, retrieval, and acquisition processes. Findings of an introspective L2 vocabulary study follow, detailing how university ESL learners reported dealing with unfamiliar words while carrying out L2 reading tasks. The information provided on their lexical inferencing strategy and varied knowledge sources used in the process provide support for the lexical components and organization proposed by Levelt. It is argued in this paper that the process of inferring the features of unknown words in a reading passage can be described in terms of lemma construction, as defined in the model.

Taalbehoud en Taalverschuiving

The results are presented of a study in which sociolinguistic language use patterns and structural characteristics of the language of three generations of Dutch immigrants to New Zealand were investigated. Language maintenance is defined as the maintenance of the L1 at one or more levels of language use, while language shift can be defined as the change in language use by an individual or a group of speakers. In a sociolinguistic questionnaire, the subjects had to report on their use of the Dutch language in domains inside and outside the home. An oral interview was conducted to establish the amount of structural language loss. The results were found to support the hypothesis based on earlier work (e.g. De Bot & Clyne, 1994; Folmer, 1991) that predicted a high level of intra- and intergenerational language shift. Structural-linguistic language loss was found to be limited, which is also in line with other findings.

Foreign Language Attrition

Compared to research on language acquisition, research on the maintenance and loss of language skills is a relatively recent development. There is, of course, a longstanding sociolinguistic tradition of research on language shift, but work in the field of attrition really started in the US in the late 1970s (Lambert and Freed 1982). Since then, research on language attrition has grown rapidly in different countries, as is witnessed by special issues devoted to the topic in the journalsApplied Psycholinguisticsin 1986,ITL-Review of Applied Linguisticsin 1989 andStudies in Second Language Acquisitionin 1989, as well as by three recent volumes: Weltens, de Bot and van Els (1986), Weltens (1989), and Seliger and Vago (1991).

Lexical processing in bilinguals

In this article data from an auditory lexical decision experiment with English-Dutch bilinguals are compared with data from a similar experiment using visual lexical decision. The aim of the experiments was to investigate three factors that may play a role in lexical processing: level of proficiency in the second language, mode of presentation (visual vs. auditory) and cognate- ness of lexical items. The structure of this article is as follows. In the first part a description is given of current theoretical models of the bilingual lexicon. In the second part we present a summary of an experiment on visual lexical decision (Kerkman, 1984; Kerkman and De Bot, 1989), and in the third part we report on the auditory lexical decision experiment. In the last part these two sets of data are discussed in the light of recent theorizing on the bilingual lexicon.

First Language Use in Second Language Production

This article reports the results of a study undertaken to provide data relevant to the development of a model of bilingual speech production. The data which we used for this purpose are 771 unintentional language switches which occurred in a 35-hour corpus of L2 learner English collected from 45 Dutch learners at 3 different proficiency levels. The occurrence of the language switches turned out to be related to the learners' proficiency in English. This finding is interpreted as support for a spreading activation account of lexical access in bilingual speakers in which the relative frequency of L1 and L2 words in the learner's repertoire plays an important role. We also examined whether our findings could be accommodated with Myers-Scotton's (1992) matrix language frame model for intrasentential code switching and with de Bot's (1992) suggestions to adapt Levelt's (1989) model of speaking for bilingual speech production. In general, this proved to be the case, but the data suggested it was also possible to draw some more specific conclusions. These concerned the storage of inflected word forms in the (bilingual) mental lexicon, the existence of a lexical checking device, and the relationship between lemma access and phonological encoding.

Immigrant Languages in Europe.

Introduction: immigrant groups and immigrant languages in Europe, Guus Extra and Ludo Verhoeven. Part 1 Use of immigrant language varieties in Europe: Sweden Finnish, Jarmo Lainio South Asian languages in Britain, Safder Alladina a bilingual perspective on Turkish and Moroccan children and adults in the Netherlands, Guus Extra and Ludo Verhoeven Croatian or Serbian as a diaspora language in Western Europe, Andrina Pavlinic. Part 2 First language acquisition in a second language context: Turkish language development in Germany, Carol Pfaff Turkish language development in the Netherlands, Anneli Schaufeli summative assessment of ethnic group language proficiency, Jeroen Aarssen et al parental attitudes towards child bilingualism in the Nordic countries, Sirkku Latomaa. Part 3 Code-switching: code-copying in immigrant Turkish, Lars Johanson Turkish-Dutch code-switching and the frame-process model, Ad Backus code-switching and borrowing in an Arabic-Dutch context, Jacomine Nortier Finns and Americans in Sweden - patterns of linguistic incorporation from Swedish, Paula Andersson. Part 4 Language maintenance and language loss: immigrant minority languages and education in Sweden, Sally Boyd Romani at the crossroads, Donald Kenrick methodological issues in language shift research, Koen Jaspaert and Sjaak Kroon lexical aspects of language attrition and shift, Kees de Bot and Bert Weltens.