This study investigated whether recasts provided during communicative interaction may improve Korean EFL learners’ accuracy with regard to regular and irregular English past tense forms, and whether individual differences in working memory capacity may intervene in the effects of recasts. To this end, forty-two Korean university students were placed into either the recast or the control group, and took the pretest and two types of working memory tests: phonological short-term and verbal. The learners participated in one-on-one conversational interactions with the researcher in three two-way communicative tasks one at a time on a weekly basis. Only the treatment group received explicit recasts on their past tense errors while the control group received no feedback of any kind. Finally, they took the posttest and completed the exit questionnaire. Results showed that recasts were beneficial for raising the learners’ accuracy level of English past tense forms, both regular and irregular, though the effects were much larger for the irregular forms. The improvements were not significantly correlated with neither of the working memory measures. Explicit and intensive recasting alone was sufficient in improving EFL learners’ English past tense accuracy in this one-on-one communicative interaction setting.

There are grammatical markers of tense that are obligatory in English and Korean, ho wever, these grammatical temporal forms are absent in Chinese. Although it is uncontrov ersial that Chinese does not morphologically encode tense, there are several other ways in which temporal information can be encoded (Smith&Erbaugh, 2005). Chinese is an aspect system language which marks aspect. On the contrast, English is a tense system languag e which marks tense. In our review of languages considered in this study, the main focus will be on aspect system and tense system which are illustrated by Chinese, English and Korean. The author will illustrate that the tense and aspect system of Chinese is different from that of Korean and English. Our argument in this paper focuses on three categories which can be referred to as the present, past and future. In chapter one, the motive of re search that difference of aspect and tense expression in Chinese, English and Korea was introduced and the course of this research was mentioned. A contrasting study was conducted in chapter two. As for contrasting the characteristics of three languages, the author hope that this paper would help to learn Chinese, English or Korean easily.

Recasts have been at the center of much di scussion in the field of second language acquisition (SLA) and a great deal of research has explored the effects of recasts on second language (L2) learning. However, there are st ill many issues and questions left to be answered. As a means of responding to these needs, the current study investigated the effectiveness of recasts in the accuracy development of child EFL learners in their use of past verb forms in English. The effectiveness of recasts was examined in relation to the type of past verbs (i.e., regular vs. irregular verbs) and the degree of exp licitness of recasts (i .e., implicit recasts vs. explicit recasts). Six elementary school students participated in the study and data were collected through a time-series design for 6 weeks. The analyses of the data showed that recasts were effective in enhancing the learners' accuracy in the use of both regular and irregular verbs. The learners benefited more from explicit recasts than implicit recasts in developing the accuracy of past verbs. However, improving the accuracy of regu lar verbs was more susceptible to explicit recasts than implicit recasts, while there was no significant difference in the gains of accuracy of irregular verbs in relation to the type of recasts.

This study examines the effects of the sequence of increasing task complexity in different modalities on the learning of the English past tense of Korean secondary learners. Robinson’s (2007) Cognition Hypothesis argued that learners pay more attention to grammatical forms in complex tasks than in less complex tasks. He suggested that tasks should be sequenced in such a way that resource-dispersing dimensions are first increased in complexity followed by an increase in the complexity of resource-directing dimensions. However, little empirical research has been done on how tasks are sequenced according to their cognitive complexity and how task modality affects second language development in the sequence. Fifty-four learners were divided into an integrated (writing with oral interaction) task group (EG 1), an oral-only task group (EG 2) and a comparison group (CG). After the sequence of six tasks was completed, one-way ANOVA revealed the EGs outperformed the CG significantly on the posttest. The mean score of EG 1 was the highest, while the improvement rate of EG 2 was the highest among the three groups. It is hoped that this result will contribute to building a solid basis on which practitioners can make decisions about sequencing tasks and implementing task modality.

To examine morphological processing of past tense in English, we set up an ERP-based experiment where the participants read stem forms of regular and irregular verbs presented by using the repetition priming paradigm: the stem forms were either preceded by their past tense forms (primed condition: walked-walk, hold-held) or by their past tense forms of unrelated verbs (unprimed condition: stayed-walk, taught-held). The difference in ERP responses between the primed and unprimed stems was taken as showing morphological priming effects. In the previous studies (e.g., Münte et al. (1999)), native speakers of English elicited the reduced N400 in regular verbs, but not in irregular verbs. However, this study found an N400 reduction in the primed condition in both regular and irregular verbs. The reduced N400 effects were also manifested in control conditions: phonological words and the regular nonce verbs. These effects show that Korean L2 learners process regular and irregular forms in an identical way, whereas native speakers processed regular and irregular forms using a dual route reported in the previous studies. To conclude, Korean L2 learners do not process morphologically as native speakers do. There are some factors that affect L2 processing. First, L1 speakers use grammatical (=morphological/syntactic) information in language processing, but L2 learners do not. According to Clahsen and Felser (2006), L2 learners' grammatical processing capacity is limited. Second, L1 is acquired implicitly by children, but L2 is learned explicitly in formal classrooms. Finally, with maturational changes, late L2 learners use a declarative memory system rather than a procedure memory system in L2 grammatical processing.