Early Childhood Development Under Two Years: Milestone Acquisition and Early Detection of Delay

The first two years of life constitute a critical window of neurodevelopmental plasticity, during which infants and toddlers acquire foundational skills across motor, language, cognitive, and socio-emotional domains. We will provide a structured overview of milestone trajectories from birth to ۲۴ months, emphasizing both normative patterns and the recognized variability within developmental ranges. Special attention will be given to the sequential acquisition of gross and fine motor abilities, the emergence of receptive and expressive language, the progression of early problem-solving and object permanence, and the evolution of attachment and social reciprocity. We will highlight red-flag indicators for developmental delay, underscore the utility of standardized screening tools in early detection, and discuss evidence-based approaches for timely referral and intervention.