Critical-thinking skills help to prepare adult education students for a successful transition to college degree programs and for job advancement. Yet fostering critical thinking poses a challenge to ESL instructors. Brookfield (2012) provides a way forward for adult educators when he explains that the crux of critical thinking is to discover one's assumptions. The author describes how instructors can model uncovering their assumptions, thus creating a safer environment for students to engage in critical thinking. Three of Brookfield's critical-thinking tasks--speaking in tongues, the critical incident questionnaire, and scenario analysis--implemented during an intermediate ESL writing course at a community college are explained. Students' responses to these tasks are summarized and reflections on both the benefits and challenges of using critical-thinking tasks in ESL classes are described.