In 1904, G. Stanley Hall coined the term “storm and stress” to describe adolescent development. More than 100 years later, this description holds true. Adolescence is the period from age 13 to emerging adulthood and is when children are transitioning into adulthood can be a tumultuous period marked by cognitive changes and social experiences. Cognitive changes include developing metacognition and the ability to think abstractly. Similar to middle childhood, the expanding social influences impact language development. In this chapter, we’ll focus first on theoretical contributions in cognitive development, then we’ll discuss cognitive and language development, and we’ll apply our understanding of cognitive development to the context of school and educational settings.