Years 1, 2, 4, 6, 8 refer to specific ages in early childhood development. During these years, children experience significant growth in physical, cognitive, and social skills. For example, by Year 1, most children can sit up and may begin to crawl, while by Year 2, they often start walking and talking in simple sentences. As children progress to Years 4, 6, and 8, they develop more complex skills. By Year 4, they typically engage in imaginative play and can follow simple instructions. By Year 6, they often start formal education, and by Year 8, they are usually more independent and capable of critical thinking, preparing them for adolescence.