This chapter explores the use of talk as a strategy that can be used in the classroom to negotiate new meaning and address incorrect scientific thinking. It focuses on the authenticity of primary 'scientists' and the nature of science work in the primary classroom. The chapter discusses the nature of science misconceptions and their impact on classroom learning. It explains the use of talk to promote effective practice in Working Scientifically. The chapter also focuses on the role of the teacher in planning for talk and eliciting children's prior knowledge though constructive dialogue. It concentrates on strategies and approaches that can be used to stimulate high-quality talk in the classroom. Science in the primary classroom typically involves group work where children interact with hands-on materials in a collaborative way. Tasks undertaken are variously known as practical work, experiments, investigations or scientific enquiry, although the latest version of the National Curriculum draws the activities together under the umbrella of Working Scientifically.