Final answer:
Language development in infancy begins with recognizing the mother's voice and progresses through stages of cooing, babbling, and speaking single words. By 12 months, infants say their first words and by 2 years, they can use around 50 words and understand many more, while also displaying logical reasoning and social interactions.
Step-by-step explanation:
The journey of language development starts with a newborn's innate ability to recognize their mother's voice and distinguish the nuances of the language spoken by their caregivers. By 6 weeks after birth, infants typically start smiling and cooing, reflecting their first attempts to communicate using simple vocalizations. As they reach approximately 6 months, the stage of babbling commences, involving repetition of syllables that signify the enhancement of their communicative skills, despite it not being directed at conveying specific messages yet.
By the time infants are 12 months old, the emergence of their first meaningful words like “mama” and “dada” marks a milestone in speech development. At this age, they are also capable of understanding and following simple commands, often accompanied by gestures.
Moving towards the end of the second year, toddlers expand their vocabulary to as many as 50 words and can understand several hundred more. Their communication includes using words and gestures to refer to objects or actions and mimic adult behaviors, displaying increased cognitive and social connections.
Around the 18-month mark, toddlers begin to combine words, showing an initial grasp of language structure and the ability to express more complex ideas. During this time, they display logical reasoning through problem-solving and exhibit greater independence, which can sometimes result in temper tantrums as they test boundaries and assert themselves.