摘要
Krashen＇s Input Hypothesis, Swain＇s Output Hypothesis, and Schmidt＇s Noticing Hypothesis are the important theories related to SLA （Second Language Acquisition）. A model based on the three is established in the present paper and used to guide students＇ writing. Some specific task types are designed to help learners know how to use words correctly and appropriately in context and thus improve their overall word use in writing. The conclusion is drawn that through conscious reading （the so-called input） and conscious imitate use of the words and expressions in the reading （the so-called output）, learners will improve the diction in writing.
