Final answer:
Children start learning to understand words said by others from birth, with rapid language development occurring from nine months to three years. By age two, they use between 50 to 200 words and by age five, they understand approximately 6,000 words and speak 2,000, and can define words and understand others' perspectives.
Step-by-step explanation:
Understanding the progression of language acquisition in young children is a fascinating aspect of developmental psychology and cognitive development. Children start learning to understand words said by others at very young ages, beginning with their ability to recognize their mother's voice and discriminate between languages at birth. When children reach the age of one, they start to utter words, such as "mama" or "ball", and can comprehend a number of words beyond those they can express. This early comprehension is crucial as they begin to follow simple commands and associate names with objects.
By the time children are between 2 to 3 years old, they often use around 50 to 200 words and understand much more. Language development sees a "vocabulary spurt" around these years, with children possibly learning 10-20 new words per week. This growth continues remarkably, and by age 5, children typically understand around 6,000 words and speak approximately 2,000 words. Not only do they understand and use a larger vocabulary, but they can also define words and ask about their meanings, as well as engage in more complex conversations.
Socioeconomic factors, as pointed out by researchers Hart and Risley, also play an essential role in the speed and breadth of language acquisition, with children from higher-income families often being exposed to a richer language environment. Moreover, by the age of five, children are developing cognitive skills, such as the theory of mind, which allows them to recognize that others have different thoughts and feelings than their own. This cognitive skill development complements their language abilities, allowing for a deeper understanding of communication and interaction with others.