Toddler Developmental Milestones

During a routine well-child visit, a nurse assesses the developmental milestones of a 2-year-old toddler. The nurse is aware that at this age, toddlers typically exhibit specific characteristics and behaviors that indicate normal development. One important aspect of this developmental stage is the ability to follow simple instructions and the understanding of basic concepts. Therefore, the nurse must evaluate whether the toddler is capable of performing tasks that involve a simple one-step direction, such as 'come here' or 'give me the ball.'

Fill in the blank: By the age of _____ years, toddlers are generally able to follow simple one-step instructions and understand some concepts, marking a significant development in their cognitive skills.