年龄和学习时间对第二语言习得的影响
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摘要
人们普遍认为儿童在第二语言学习方面要优越于成人。尤其是他们在语音方面的特殊能力给人留下了深刻的印象。而这也成为了从小学开始外语教学的一个普遍依据。文中笔者回顾了关于开始学习外语的时间和学习时间长度对第二语言习得影响的研究。并探讨了造成儿童、少年和成人在第二语言习得中的不同表现的一些重要理论和假说。最后笔者对六十名学生做了一个语音测试，以探寻开始学习外语的年龄以及学习时间的长短对语音能力的影响。
It is generally held that children are superior to adults at second language acquisition. And their impressive ability to achieve a more native-like pronunciation of a foreign language than older students is the most common reason given for beginning foreign languages in the elementary school. In this paper previous research on the influence of Starting Age and Length of Learning on the SLA is reviewed. And some important theories and hypotheses are given to account for the different performance of child, adolescent and adult on second language learning. And at the end a pronunciation test was carried out to examine the relationships among starting age, length of learning and one's pronunciation proficiency.
It is generally held that children are superior to adults at second language acquisition. And their impressive ability to achieve a more native-like pronunciation of a foreign language than older students is the most common reason given for beginning foreign languages in the elementary school. In this paper previous research on the influence of Starting Age and Length of Learning on the SLA is reviewed. And some important theories and hypotheses are given to account for the different performance of child, adolescent and adult on second language learning. And at the end a pronunciation test was carried out to examine the relationships among starting age, length of learning and one's pronunciation proficiency.
引文
Andersson, T. Foreign Languages in the Elementary School. Austin, Texas: University of Texas Press, 1969.
Asher, J. J. Toward a neo-field theory of behavior. Journal of Humanistic Psychology. 1964, 4, 85-94.
Asher, J., and Price, B. The learning strategy of the total physical response: some age differences. Child Development. December 1967, 38 (4), 1219-1227.
Asher, J., and Garcia, R. The optimal age to learn a foreign language. The Modern Language Journal. 1969, 53, 334-41.
Ausubel, D. Adults versus children in second-language learning: psychological considerations. Modern Language Journal. 1964, 48, 42-424.
Bailey, N., and Madden, C. Is second language learning like first language learning? Paper presented at the Third Annual Conference of the City University of New York, 1973.
Berko, J. The child's learning of English morphology. Word. 1958, 14, 150-177.
Bland, M., and Keislar, E. R. A self-controlled audio-lingual program for children. French Review. 1966, 40, 266-276.
Buffery, A. The neuropsychology of language development: an essay on cerebral dominance. In N. Waterson and C. E. Snow (eds.), The Development of Communication: Social and Pragmatic Factors in Language Acquisition. London: Wiley, 1978.
Burstall, C. French in the primary school: The British experiment. Canadian Modern Language Review. 1975, 31, p.17.
Carroll, J. B. Research on teaching foreign languages. In N. L. Gage (ed.), Handbook of Research on Teaching. Chicago: Rand McNally, 1963, 1060-1100.
Carroll, J. The prediction of success in intensive foreign language training. In R. Glazer (ed.), Training Research and Education. University of Pittsburgh:
Pittsburgh, 1963.
Cazden, C., Cancino, H., Rosansky, E., and Schumann, J. Second language acquisition sequences in children, adolescents, and adults. Final Report, United States Department of Health, Education, and Welfare, 1975.
Chastain, K. Affective and ability factors in second-language acquisition. Language Learning. 1975, 25, 153-161.
Chomsky, N. Review of Verbal Behavior by B. F. Skinner. Language. 1959, 35, 26-58.
Cook, V. J. Chomsky's Universal Grammar. London: Basil Blackwell, 1988.
Donoghue, M. Foreign Languages and the Elementary School Child. Dubugue: William C. Brown Publishers, 1968.
Dulay, H., and Burt, M. Natural sequences in child second language acquisition. Working Papers in Bilingualism, 1974 (4), 71-98.
Dulay, H., Krashen, S., and Burt, M. Language Two. New York: Oxford University Press, 1982.
Dunkel, H. B., and Pillet, R. A. A second year of French in elementary school. Elementary School Journal. 1957, 53, 143-151.
Ekstrand, L. H. Evaluation of teaching technique and results on the basis of recorded tests from pupils in grades 1, 2, 3, and 4. Stenciled, National Board of Education, 1959.
Ekstrand, L. H. Adjustment among immigrant pupils in Sweden. Paper presented to the 18th International Congress of Applied Psychology, Montreal, 1974.
Ervin-Tripp, S. Is second language learning like the first? TESOL Quarterly. 1974, 8, 111-127.
Fathman, A. The relationship between age and second language productive ability. Language Learning. 1975, 25, 245-253.
Gardner, R., and Lambert, W. Attitudes and Motivation in Second-Language Learning. Rowley, Mass.: Newbury House, 1972.
Gardner, R. C. Social Psychology and Second Language Learning: The Role of
Attitudes and Motivation. London: Edward Arnold. 1985, p.39, 54.
Genesee, F. The role of intelligence in second language learning. Language Learning. 1976, 26, 148-150.
Gleitman, L., and Gleitman, H. Phrase and Paraphrase. New York: Holt, Rinehart and Winston, 1970, p.56.
Gliksman, L. Second Language Acquisition: the Effects of Students' Attitudes on Classroom Behavior. Unpublished MA thesis, University of Western Ontario, 1976.
Grinder, R. E., Otomo, A., and Toyota, W. Comparison between second, third, and fourth grade children in the audio-lingual learning of Japanese as a second language. Department of Psychology, University of Hawaii, Honolulu, 1961.
Guiora, A., Beit-Hallahami, B., Brannon, R., Dull, C., and Scovel, T. The effects of experimentally induced changes in ego states on pronunciation ability in a second language: An exploratory study. Comprehensive Psychiatry. 1972, 13,421-8.
Hatch, E. Optimal age or optimal learners? UCLA: Workpapers in Teaching English as a Second Language. 1975, 11, 45-56.
Hatch, E., Simplified input and second language acquisition. Paper presented at the 1979 LSA Conference, Los Angeles, California, 1979.
Heyde, A. The relationship between self-esteem and oral production of a second language. In H. D. Brown, D. A. Yorio and R. H. Crymes (eds.), On TESOL'77: Teaching and Learning English as a Second Language. Washington, D.C.: TESOL, 1977.
Johnson, J., and Newport, E. Critical period effects in second language learning: The influence of maturational state on the acquisition of English as a second language. Cognitive Psychology. 1989, 21, 60-99.
Kinsbourne, M. The ontogeny of cerebral dominance. In D. Aaronson and R. W. Rieber (eds.), Developmental Psycholinguistics and Communication Disorders. New York: New York Academy of Sciences, 1975.
Kirch, M. S. At what age elementary school language teaching? Modern Language Journal. 1956, 40, 399-400.
Krashen, S., and Harshman, R. Lateralization and the critical period. UCLA Working Papers in Phonetics. 1972, 23, 13-21.
Krashen, S. Lateralization, language learning, and the critical period: Some new evidence. Language Learning. 1973, 23, 63-74.
Krashen, S., Seliger, H., and Harnett, D. Two studies in adult second language learning. Kritikon Litterarum. 1974, 2/3, 220-228.
Krashen, S. The critical period for language acquisition and its possible bases. In D. Aaronson and R. W. Rieber (eds.), Developmental Psycholinguistics and Communication Disorders. New York: New York Academy of Sciences, 1975.
Krashen, S., and Seliger, H. The role of formal and informal environments in adult second language learning. International Journal of Psycholinguistics. 1976, 3, 15-21.
Krashen, S. The Monitor Model for adult second language performance. In M. Burt, H. Dulay and M. Finocchiaro (eds.), Viewpoints on English as a Second Language. New York: Regents, 1977, 152-161.
Krashen, S., Jones, C., Zelinski, S., and Usprich, C. How important is instruction? English Language Teaching Journal. 1978, 32, 257-261.
Krashen, S. Adult second language acquisition and learning: A review of theory and practice. In R. Gingras (ed.), Second Language Acquisition and Foreign Language Learning. Washington: Center for Applied Linguistics, 1978.
Krashen, S. Individual variation in the use of monitor. In W. Ritchie (ed.), Principles of Second Language Learning. New York: Academic Press, 1978.
Krashen, S., Long, M. and Scarcella, R. Age, rate and eventual attainment in second language acquisition. TESOL Quarterly. 1979, 13, (4), 573-582.
Krashen, S. The Input Hypothesis, Paper presented at the Georgetown 1980
Roundtable Discussion. Georgetown University Press, 1980.
Krashen, S. The theoretical and practical relevance of simple codes in second language acquisition. In R. Scarcella and S. Krashen (eds.), Research in Second Language Acquisition. Rowley, Mass.: Newbury House, 1980.
Krashen, S. Attitude and aptitude in relation to second language acquisition and learning. In K. Diller (ed.), Individual Differences and Universals in Language Learning Aptitude. Rowley, Mass.: Newbury House, 1980.
Krashen, S., Scarcella, R., and Long, M. Child-adult differences in Second language acquisition. In Series on Issues in Second Language Research. Rowley, Mass.: Newbury House, 1982.
Lambert, W. E., Gardner, R. C., Olton, R., and Tunstall, K. A study of the roles of attitudes and motivation in second-language learning. In J. A. Fishman (ed.), Readings in the Sociology of Language. The Hague, 1968.
Lambert, W. E., and MacNamara, J. Some cognitive consequences of following a first grade curriculum in a second language. Journal of Educational Psychology. 1969, 40 (2), 86-90.
Lenneberg, E. Biological Foundations of Language. New York: Wiley & Sons, 1967.
Lenneberg, E. On explaining language. Science, 1969, 165, 635-643.
Long, M. Towards a neurolinguistic explanation for the effect of age on secondary language acquisition. Unpublished paper, 1978.
Long, M. Questions in Foreigner Talk Discourse. Paper presented at the 1980 TESOL Convention, San Francisco, 1980.
Macnamara, J. The cognitive strategies of language learning. In J. W. Oiler, Jr and J. C. Richards, Focus on the learner: Pragmatic Perspectives for the Language Teacher Rowley, Mass.: Newbury House, 1973.
Mackey, W. Language Teaching Analysis. London: Longman, 1965.
Meisel, J. M. Linguistic simplification. In W. Felix (ed.), Second Language Development: Trends and Issues. Gunter Narr Velag Tubingen, 1980.
Oller, J., Hudson, A. and Liu, P. Attitudes and attained proficiency in ESL: a
sociolinguistic study of native speakers of Chinese in the United States. Language Learning, 1977, 27, 1-27.
Olson, L. L., and Samuels, S. J. The relationship between age and accuracY of foreign language pronunciation. Journal of Educational Research. 1973, 66.
Oyama, S. A sensitive period for the acquisition of a second language. Ph.D. dissertation. Harvard University, 1973.
Patkowski, M. The sensitive period for the acquisition of syntax in a second language. Language Learning. 1980, 30, 449-72.
Penfield, W. and Roberts, L. Speech and Brain-Mechanisms. Princeton: Princeton University Press, 1959.
Scarcella, R. Developing conversational competence through role-play. Paper presented at the 1977 CATESOL conference, San Francisco, 1977.
Scarcella, R. "Watch up": A study of verbal routines in adult second language performance. Working Papers in Bilingualism. 1979.
Schumann, J. Affective factors and the problem of age in SLA. Language Learning. 1975, 2, 130, 229-30.
Scovel, T. Foreign accents, language acquisition and cerebral dominance. Language Learning. 1969, 19, 245-253.
Seliger, H., Krashen, S., and Ladefoged, P. Maturational constraints in the acquisition of a native like accent in second language learning. Language Sciences. 1975 (36), 20-22.
Seliger, H. Implications of a multiple critical periods hypothesis for second language learning. In W. Ritchie (ed.), Second Language Acquisition Research. New York: Academic Press, 1978, 11-19.
Snow, C. E., and Hoefnagel-Hohle, M. The critical period for language acquisition: evidence from second-language learning. Child Development. 1978, 49, 1114-28.
Snow, C. E., and Hoefnagel-Hohle, M. Age differences in the pronunciation of foreign sounds. Language and Speech. 1977, 4, 357-365.
Stevick, E. Memory, Meaning and Method. Rowley, Mass.: Newbury House, 1976.
Toukomaa, P. On the language development and school progress of Finnish immigrant pupils in the Swedish comprehensive school. Paper presented to the Scandinavian Seminar on Language Policy, Helsinki, 1975.
Van Dongen, H. R., and Loonen, M. C. B. Neurological factors related to prognosis of acquired aphasia in childhood. In Y. Lebrun and R. Hoops (eds.), Recovery in Aphasics. Amsterdam: Swets & Zeitlinger, 1976.
Wagner-Gough, J., and Hatch, E. The importance of input data in second language acquisition studies. Language Learning. 1975, 25, 297-308.
Walburg, H., Hase, K. and Pinzur Rasher, S. English acquisition as a diminishing function of experience rather than age. TESOL Quarterly. 1978, 12, 4, 427-437.
Wesche, M. Vygotsky and the Social Formation of Mind. Cambridge, Mass.: Harvard University Press, 1977.
White, L. Universal grammar as a source of explanation in second language acquisition. In B. Wheatley et al. (eds.): Current Approaches to Second Language Acquisition. Bloomington, Ind.: Indiana University Linguistics Club, 1985.
Asher, J. J. Toward a neo-field theory of behavior. Journal of Humanistic Psychology. 1964, 4, 85-94.
Asher, J., and Price, B. The learning strategy of the total physical response: some age differences. Child Development. December 1967, 38 (4), 1219-1227.
Asher, J., and Garcia, R. The optimal age to learn a foreign language. The Modern Language Journal. 1969, 53, 334-41.
Ausubel, D. Adults versus children in second-language learning: psychological considerations. Modern Language Journal. 1964, 48, 42-424.
Bailey, N., and Madden, C. Is second language learning like first language learning? Paper presented at the Third Annual Conference of the City University of New York, 1973.
Berko, J. The child's learning of English morphology. Word. 1958, 14, 150-177.
Bland, M., and Keislar, E. R. A self-controlled audio-lingual program for children. French Review. 1966, 40, 266-276.
Buffery, A. The neuropsychology of language development: an essay on cerebral dominance. In N. Waterson and C. E. Snow (eds.), The Development of Communication: Social and Pragmatic Factors in Language Acquisition. London: Wiley, 1978.
Burstall, C. French in the primary school: The British experiment. Canadian Modern Language Review. 1975, 31, p.17.
Carroll, J. B. Research on teaching foreign languages. In N. L. Gage (ed.), Handbook of Research on Teaching. Chicago: Rand McNally, 1963, 1060-1100.
Carroll, J. The prediction of success in intensive foreign language training. In R. Glazer (ed.), Training Research and Education. University of Pittsburgh:
Pittsburgh, 1963.
Cazden, C., Cancino, H., Rosansky, E., and Schumann, J. Second language acquisition sequences in children, adolescents, and adults. Final Report, United States Department of Health, Education, and Welfare, 1975.
Chastain, K. Affective and ability factors in second-language acquisition. Language Learning. 1975, 25, 153-161.
Chomsky, N. Review of Verbal Behavior by B. F. Skinner. Language. 1959, 35, 26-58.
Cook, V. J. Chomsky's Universal Grammar. London: Basil Blackwell, 1988.
Donoghue, M. Foreign Languages and the Elementary School Child. Dubugue: William C. Brown Publishers, 1968.
Dulay, H., and Burt, M. Natural sequences in child second language acquisition. Working Papers in Bilingualism, 1974 (4), 71-98.
Dulay, H., Krashen, S., and Burt, M. Language Two. New York: Oxford University Press, 1982.
Dunkel, H. B., and Pillet, R. A. A second year of French in elementary school. Elementary School Journal. 1957, 53, 143-151.
Ekstrand, L. H. Evaluation of teaching technique and results on the basis of recorded tests from pupils in grades 1, 2, 3, and 4. Stenciled, National Board of Education, 1959.
Ekstrand, L. H. Adjustment among immigrant pupils in Sweden. Paper presented to the 18th International Congress of Applied Psychology, Montreal, 1974.
Ervin-Tripp, S. Is second language learning like the first? TESOL Quarterly. 1974, 8, 111-127.
Fathman, A. The relationship between age and second language productive ability. Language Learning. 1975, 25, 245-253.
Gardner, R., and Lambert, W. Attitudes and Motivation in Second-Language Learning. Rowley, Mass.: Newbury House, 1972.
Gardner, R. C. Social Psychology and Second Language Learning: The Role of
Attitudes and Motivation. London: Edward Arnold. 1985, p.39, 54.
Genesee, F. The role of intelligence in second language learning. Language Learning. 1976, 26, 148-150.
Gleitman, L., and Gleitman, H. Phrase and Paraphrase. New York: Holt, Rinehart and Winston, 1970, p.56.
Gliksman, L. Second Language Acquisition: the Effects of Students' Attitudes on Classroom Behavior. Unpublished MA thesis, University of Western Ontario, 1976.
Grinder, R. E., Otomo, A., and Toyota, W. Comparison between second, third, and fourth grade children in the audio-lingual learning of Japanese as a second language. Department of Psychology, University of Hawaii, Honolulu, 1961.
Guiora, A., Beit-Hallahami, B., Brannon, R., Dull, C., and Scovel, T. The effects of experimentally induced changes in ego states on pronunciation ability in a second language: An exploratory study. Comprehensive Psychiatry. 1972, 13,421-8.
Hatch, E. Optimal age or optimal learners? UCLA: Workpapers in Teaching English as a Second Language. 1975, 11, 45-56.
Hatch, E., Simplified input and second language acquisition. Paper presented at the 1979 LSA Conference, Los Angeles, California, 1979.
Heyde, A. The relationship between self-esteem and oral production of a second language. In H. D. Brown, D. A. Yorio and R. H. Crymes (eds.), On TESOL'77: Teaching and Learning English as a Second Language. Washington, D.C.: TESOL, 1977.
Johnson, J., and Newport, E. Critical period effects in second language learning: The influence of maturational state on the acquisition of English as a second language. Cognitive Psychology. 1989, 21, 60-99.
Kinsbourne, M. The ontogeny of cerebral dominance. In D. Aaronson and R. W. Rieber (eds.), Developmental Psycholinguistics and Communication Disorders. New York: New York Academy of Sciences, 1975.
Kirch, M. S. At what age elementary school language teaching? Modern Language Journal. 1956, 40, 399-400.
Krashen, S., and Harshman, R. Lateralization and the critical period. UCLA Working Papers in Phonetics. 1972, 23, 13-21.
Krashen, S. Lateralization, language learning, and the critical period: Some new evidence. Language Learning. 1973, 23, 63-74.
Krashen, S., Seliger, H., and Harnett, D. Two studies in adult second language learning. Kritikon Litterarum. 1974, 2/3, 220-228.
Krashen, S. The critical period for language acquisition and its possible bases. In D. Aaronson and R. W. Rieber (eds.), Developmental Psycholinguistics and Communication Disorders. New York: New York Academy of Sciences, 1975.
Krashen, S., and Seliger, H. The role of formal and informal environments in adult second language learning. International Journal of Psycholinguistics. 1976, 3, 15-21.
Krashen, S. The Monitor Model for adult second language performance. In M. Burt, H. Dulay and M. Finocchiaro (eds.), Viewpoints on English as a Second Language. New York: Regents, 1977, 152-161.
Krashen, S., Jones, C., Zelinski, S., and Usprich, C. How important is instruction? English Language Teaching Journal. 1978, 32, 257-261.
Krashen, S. Adult second language acquisition and learning: A review of theory and practice. In R. Gingras (ed.), Second Language Acquisition and Foreign Language Learning. Washington: Center for Applied Linguistics, 1978.
Krashen, S. Individual variation in the use of monitor. In W. Ritchie (ed.), Principles of Second Language Learning. New York: Academic Press, 1978.
Krashen, S., Long, M. and Scarcella, R. Age, rate and eventual attainment in second language acquisition. TESOL Quarterly. 1979, 13, (4), 573-582.
Krashen, S. The Input Hypothesis, Paper presented at the Georgetown 1980
Roundtable Discussion. Georgetown University Press, 1980.
Krashen, S. The theoretical and practical relevance of simple codes in second language acquisition. In R. Scarcella and S. Krashen (eds.), Research in Second Language Acquisition. Rowley, Mass.: Newbury House, 1980.
Krashen, S. Attitude and aptitude in relation to second language acquisition and learning. In K. Diller (ed.), Individual Differences and Universals in Language Learning Aptitude. Rowley, Mass.: Newbury House, 1980.
Krashen, S., Scarcella, R., and Long, M. Child-adult differences in Second language acquisition. In Series on Issues in Second Language Research. Rowley, Mass.: Newbury House, 1982.
Lambert, W. E., Gardner, R. C., Olton, R., and Tunstall, K. A study of the roles of attitudes and motivation in second-language learning. In J. A. Fishman (ed.), Readings in the Sociology of Language. The Hague, 1968.
Lambert, W. E., and MacNamara, J. Some cognitive consequences of following a first grade curriculum in a second language. Journal of Educational Psychology. 1969, 40 (2), 86-90.
Lenneberg, E. Biological Foundations of Language. New York: Wiley & Sons, 1967.
Lenneberg, E. On explaining language. Science, 1969, 165, 635-643.
Long, M. Towards a neurolinguistic explanation for the effect of age on secondary language acquisition. Unpublished paper, 1978.
Long, M. Questions in Foreigner Talk Discourse. Paper presented at the 1980 TESOL Convention, San Francisco, 1980.
Macnamara, J. The cognitive strategies of language learning. In J. W. Oiler, Jr and J. C. Richards, Focus on the learner: Pragmatic Perspectives for the Language Teacher Rowley, Mass.: Newbury House, 1973.
Mackey, W. Language Teaching Analysis. London: Longman, 1965.
Meisel, J. M. Linguistic simplification. In W. Felix (ed.), Second Language Development: Trends and Issues. Gunter Narr Velag Tubingen, 1980.
Oller, J., Hudson, A. and Liu, P. Attitudes and attained proficiency in ESL: a
sociolinguistic study of native speakers of Chinese in the United States. Language Learning, 1977, 27, 1-27.
Olson, L. L., and Samuels, S. J. The relationship between age and accuracY of foreign language pronunciation. Journal of Educational Research. 1973, 66.
Oyama, S. A sensitive period for the acquisition of a second language. Ph.D. dissertation. Harvard University, 1973.
Patkowski, M. The sensitive period for the acquisition of syntax in a second language. Language Learning. 1980, 30, 449-72.
Penfield, W. and Roberts, L. Speech and Brain-Mechanisms. Princeton: Princeton University Press, 1959.
Scarcella, R. Developing conversational competence through role-play. Paper presented at the 1977 CATESOL conference, San Francisco, 1977.
Scarcella, R. "Watch up": A study of verbal routines in adult second language performance. Working Papers in Bilingualism. 1979.
Schumann, J. Affective factors and the problem of age in SLA. Language Learning. 1975, 2, 130, 229-30.
Scovel, T. Foreign accents, language acquisition and cerebral dominance. Language Learning. 1969, 19, 245-253.
Seliger, H., Krashen, S., and Ladefoged, P. Maturational constraints in the acquisition of a native like accent in second language learning. Language Sciences. 1975 (36), 20-22.
Seliger, H. Implications of a multiple critical periods hypothesis for second language learning. In W. Ritchie (ed.), Second Language Acquisition Research. New York: Academic Press, 1978, 11-19.
Snow, C. E., and Hoefnagel-Hohle, M. The critical period for language acquisition: evidence from second-language learning. Child Development. 1978, 49, 1114-28.
Snow, C. E., and Hoefnagel-Hohle, M. Age differences in the pronunciation of foreign sounds. Language and Speech. 1977, 4, 357-365.
Stevick, E. Memory, Meaning and Method. Rowley, Mass.: Newbury House, 1976.
Toukomaa, P. On the language development and school progress of Finnish immigrant pupils in the Swedish comprehensive school. Paper presented to the Scandinavian Seminar on Language Policy, Helsinki, 1975.
Van Dongen, H. R., and Loonen, M. C. B. Neurological factors related to prognosis of acquired aphasia in childhood. In Y. Lebrun and R. Hoops (eds.), Recovery in Aphasics. Amsterdam: Swets & Zeitlinger, 1976.
Wagner-Gough, J., and Hatch, E. The importance of input data in second language acquisition studies. Language Learning. 1975, 25, 297-308.
Walburg, H., Hase, K. and Pinzur Rasher, S. English acquisition as a diminishing function of experience rather than age. TESOL Quarterly. 1978, 12, 4, 427-437.
Wesche, M. Vygotsky and the Social Formation of Mind. Cambridge, Mass.: Harvard University Press, 1977.
White, L. Universal grammar as a source of explanation in second language acquisition. In B. Wheatley et al. (eds.): Current Approaches to Second Language Acquisition. Bloomington, Ind.: Indiana University Linguistics Club, 1985.