Essays on second language teaching focuses on how the kinds of tasks performed by the learner relate to language output. "Choosing and Using Communication Tasks for Second Language Instruction" (Teresa Pica, Ruth Kanagy, Joseph Falodun) contains a taxonomy of communication task types, based on the concepts of goal and activity, particularly with reference to classroom pedagogy and learning theory. "Interlocutor and Task Familiarity: Effects on Interactional Structure" (India Plough, Susan M. Gass) looks at the extent to which task participants' familiarity with each other and with task type affect the linguistic outcome. "Tasks and Interlanguage Performance: An SLA Research Perspective" (Patricia A. Duff) presents naturalistic research on an immigrant's second language acquisition, focusing on lexical variety and syntax (nominal reference and negotiation). In "Variation in Foreigner Talk Input: The Effects of Task and Proficiency" (Ian M. Shortreed), the study is concerned with the effects of task complexity and learner proficiency on linguistic reduction and on communication and repair strategies. "Grammar and Task-Based Methodology" (Lester Loschky, Robert Bley-Vroman) argues that despite the communicative orientation of tasks in materials and curricula, there is a role for tasks in structurally-oriented second language teaching. (MSE)