Set in the context of Hong Kong's school curriculum reform initiative, which centers on development and implementation of task-based instruction, a study examined: (1) what teachers of English as a Second Language understand about language learning and what decisions they make when preparing a classroom task; (2) to what extent elementary and secondary teachers differ in their interpretations of tasks; and (3) the factors influencing those interpretations. A total of 114 (43 secondary, 71 primary) teachers of English attending an in-service teacher education program on the new curriculum were surveyed and interviewed concerning the lesson planning process. Results suggest that the teachers had a tacit understanding of how to develop and adapt a task description for classroom instructional use. Teachers indicated a need for more preparation in classroom management techniques and in offering language support to students. Three tables present response categories for post-questions, criteria for task interpretation, and criteria for holistic interpretations. Contains 22 references, an appendix containing the outline for an activity on lesson planning, and a table for inter-rater reliability. (MSE)