3. AGE Younger L2 learner generally does better than older learners. Critical Period Hypothesis There is a fixed span of years during which language learning can take place naturally and effortlessly, and after which it is not possible to be completely successful. Widely Held Lay Belief

4. Penfield and Roberts (1959), Optimum period for language acquisition falls within the first ten years of life, when the brain retains its plasticity. Initially, this period was equated with the period taken for lateralization of the language function to the left side of the brain to be completed. Work on children and adults who had experienced brain injuries or operations indicated that damage to the left hemisphere caused few speech disorders and was rapidly repaired in the case of children but not adults (Lenneberg 1967).

5. Reason for the lack of consensus on the age issue Difficulty of comparing the results of studies Methods Performance Measures

6. Methods Longitudinal Cross Sectional Experimental Groups of learners Groups of learners 1. Same Starting Time Snow, Hoefnagel, Hohle (1978) 2. Different Starting times Burstall (1975) 1 Individuals Began L2 2. Number of Years Oyama (1976) Investigates the Effects of attempts to teach learners varying in age specific features of an L2. Neufeld (1978)

7. Performance Measures The studies have also varied in how they have measured learning. Performance measures based on samples of planned or unplanned language use have been used. Grammaticality judgments of learners of different ages have been examined. (Coppieters 1987 ) Native speakers have been asked to rate the performance of mixed groups of learners and native speakers in terms of how native their use of the language is. (Scovel 1981)

8. The result obtained by these studies fails to agree. As Larsen Freeman and Long (1991) The age issue remains an important one 1. For Theory building in SLA Research 2. For Educational policy making 3. For Language pedagogy

9. The younger learner do better that older learners The case for an early start in foreign language education is strengthened . Children learn in different ways to adults Language teachers will need to identify different approaches and techniques to suit the two kinds to learners.

11. Effects of age according to learning context Naturalistic Instructed learning context

12. 1. The effects of age on rate of second language learning. Krashen, Long, and Scarcella (1979) conclude that (1) adults are superior to children in rate of acquisitions (2) older children learn more rapidly than younger children. The study most often cited in support of these conclusions is Snow and Heofnaggle-Hohle (1978).

13. Grammar Syntax and Morphology Pronunciation Children GOOD Adolescents BETTER Adults BEST Children BEST Adults GOOD Adolescents BETTER

14. Adults outperform children in the short term. Oslen and Samuels (1973) Children outperform adults, This research supported to Krashen, Long and Scarcellas’. Cochrani (1980) EXPERIMENTAL STUDIES Controversy

16. The effect of age on the acquisition of native speaker proficiency. Effect of age on the achievement of native speaker level of proficiency is controversial point. .Comparisons have been made with the critical period hypothesis.

37. SOME GENERAL CONCLUSIONS. The research that has addressed the age issue is quite enormous. Not surprisingly, commentators have arrived at different conclusions, but despite this some common ground is emerging. 1. Adult learners have an initial advantage where rate of learning is concerned, particularly in grammar. They will eventually be overtaken by child learners who receive enough exposure to the L2. This is less likely to happen in instructional than in naturalistic settings because the critical amount of exposure is usually not available in the former.

38. 2. Only child learners are capable of acquiring a native accent in informal learning contexts. Long (1990a) puts the critical age at 6 years, but Scovel argues that there is no evidence to support this and argues for a pre puberty start. Singleton (1989) points out those children will only acquire a native accent if they receive massive exposure to the L2. However, some children who receive this exposure still do not achieve a native like accent, possibly because they strive to maintain active use of their L1. Adult learners may be able to acquire a native accent with the assistance of instruction, but further research is needed to substantive this claim.

39. 3.Children may be more likely to acquire a native grammatical competence. The critical period for grammar may be later than for pronunciation (around 15 years.) Some adult learners, however, may succeed in acquiring native level of grammatical accuracy in speech and writing and even full linguistic competence, 4. Irrespective of whether native speaker proficiency is achieved, children are more likely to reach higher level of attainment in both pronunciation and grammar than adults.

41. Explaining the role of age in second language acquisition These general conclusions provide substantial support for the existence of at least a sensitive period for L2 acquisition. A number of explanations have been advanced to account for the existence of a critical or sensitive period. These have been admirably reviewed in Singleton (1989) and Long (19904, and are summarized in Table.

42. One of the major points of controversy is whether the differences between child and adult learners are to be explained as primarily the result of environmental factors or of changes in the mental and neurological mechanisms responsible for language learning. Muhlhauser (1986), after an extensive study of the developmental stages of Pidgin languages and their similarities to language acquisition, concludes that adults and children appear to behave very much in the same manner which indicates that ‘activation of certain linguistic developments is dependent on the presence of specific environmental factors, rather than on different cognitive abilities of children and adults’ (198& 265—s). Long, on the other hand, concludes that a neurological explanation is best and proposes the attractive-sounding ‘ mental muscle model’

43. Long’s ‘mental muscle model’, therefore may not provide a satisfactory explanation where L2 phonology is concerned, but seems to offer a convincing account of why child and adult learners do not differ in the process of acquiring an L2 grammar.

44. CONCLUSION To conclude, it is not yet possible to reach an> definite decisions on such key issues as whether adults have continued access to a language-specific acquisition device such as Universal Grammar. One tentative conclusion suggested by the research is that the acquisition of phonology (which appears to be particularly sensitive to age) proceeds somewhat differently from the acquisition of grammar (which appears much less sensitive).

45. There are changes in the neurological structure of the brain at certain ages which affect learner’s abilities to acquire L2 pronunciation and grammar. Various accounts of the nature of these changes have been proposed to account for the loss of plasticity that occurs with age (e.g. lateralization and cerebral maturation). Neurological the language learning capacity of adults is impaired by deterioration in their ability to perceive and segment sound in an L2. Sensory acuity

46. Adult learner on general inductive learning abilities to learning abilities to learn and L2 while children use their language acquisition device. Cognitive factors Child learners are more strongly motivated to communicate with native speakers and to integrate culturally. Also child learners are less conscious and therefore suffer less from anxiety about communicating in an L2. Affective Motivational factors.

47. Children store L1 and L2 information separately (i.e. become coordinate bilinguals) adults store L1 and L2 knowledge together (i.e. become compound bilinguals.) Storage of L2 information The language input received by children is superior to that received by adults. However, adults may experience more negotiation of meaning Input