Long's Interaction Hypothesis(1996)suggests that interaction facilitates second language development because during interaction learners may receive feedback regarding the linguistic success or failure of their utterances.A number of SLA researchers have investigated the effectiveness of recasts, prompts, and models as widely used types of feedback in second language classroom ignoring the roles of teachers' intents and learners' percepts. Some SLA researchers argue the ambiguity of such interactional feedback to the learners.The main purpose of this book is to investigate teachers' intents materialized in prosodic features, length of feedback, and paralinguistic devices on diminishing the ambiguity of liguistic reacsts, prompts, and models when they are used as focus on form techniques. The results proved a significant relationship between teachers' intents and learners'percepts in recasts in providing feedback in prosodic features, length of feedback, and paralinguistic devices, while in prompts and models showed different results. This book carries significant implications for SLA researchers and language teachers in EFL contexts.