This chapter discusses the nature of reading difficulties and summarizes current understanding of best practice in associated reading interventions with focus on the English and Chinese languages. In particular, it reviews the causes, characteristics and consequences of children with dyslexia and those with late-emerging reading difficulties (LRD) whose problems with reading manifest themselves at senior primary grades. Students with LRD tend to show signs in the senior primary grades, and LRD is estimated to affect 20% to 46% of school-age children. In this chapter, the characteristics of the English and Chinese languages and the essential features influencing cognitive-linguistic development necessary to understand children with dyslexia and LRD are also discussed. Understanding the cognitive-linguistic causes and the mechanisms underlying dyslexia and LRD allows better-informed identification and intervention for further work on research and practice.