This present study concerned whether prompts and recasts that occur during interaction could play a role in L2 development. Adopting an untimed grammatical judgment test and an elicited oral imitation test to measure explicit and implicit knowledge, this study examined the relative effects of prompts and recasts on L2 development of past tense forms. The participants were pre-intermediate learners enrolled in English as a foreign language (EFL) classes at a university in Korea. The learners were assigned to two prompt groups, a recast group, and a control group. The analysis of the untimed grammaticality judgment test revealed that the participants promoted their explicit knowledge of the past tense forms of regular and irregular verbs when prompts were provided. The analysis also showed that the learners who received recasts improved their test scores but only in irregular past tense forms. No significant group difference was found among the treatment groups and the control group in the results of the elicited oral imitation test used to measure implicit knowledge of the target forms. These results indicated that prompts were beneficial for short-term L2 grammatical learning of EFL learners of pre-intermediate level. The implications and limitations are discussed in terms of the role of prompts in driving L2 development.

I. INTRODUCTION
II. LITERATURE REVIEW
III. METHOD
    1. Participants
    2. Target Forms
    3. Design
    4. Materials
    5. Procedure
    6. Analysis
IV. RESULTS
    1. Overall Effects of Prompts and Recasts
    2. L2 Learning of Regular and Irregular Past Tense
V. DISCUSSION
VI. CONCLUSION
REFERENCES

• Hyewon Cho(Far East University)