Linguistic development in children

At birth, a child's earliest vocalisations are crying and laughter, which then progresses to cooing (e.g., oooh) and babbling (e.g., bababa) between two to four months old (Bjorklund, 2005). Children typically speak their first words at approximately 10 to 12 months of age; early words usually refer to family members (e.g., Mama, Dada) and the names of important places and objects (e.g., toys and food). At approximately 18 to 24 months, children start to speak in two-word utterances (e.g., go park) and continue to use the words that are most important to them. Children at this age often use gestures and intonation to make up for their limited language; for example, a child saying "Mummy" and waving an empty cup becomes a request for a refill. As such, receptive language (i.e., what a child can understand) is better developed than productive language (i.e., what a child can speak) at this stage (Bjorklund, 2005).

When children move beyond two-word utterances, they tend to only include the words that convey the most meaning (high-content words) and leave out the words that make language easy to understand (if, and, but) but are not a necessity for comprehension. For example, a child aged around 30 months old might say "Daddy give milk me" rather than "Give me the milk daddy". Children at this age tend to be highly selective in their choice of words using only the high information words that are most important in conveying meaning (Bjorklund, 2005).

Once children begin to learn the rules of syntax, they tend to over-apply it, which is known as overregulation. For example, a child may learn that adding "ed" to the end of a verb is necessary to make it past tense (e.g., walked) or adding "s" to the end of a noun makes it plural (e.g., oranges). Children do not understand at this stage that there are irregular verbs and nouns. Words such as "runned", "drinked", "waked", and "feets" may follow the rules but they are incorrect. Overregulation often continues until children are approximately three years old when it begins to significantly decrease (Bjorklund, 2005; Smith et al., 2003).

During the preschool years, children begin to learn words at an accelerated rate; a phenomenon known as the word spurt. Most of the words that children learn during this word spurt are nouns, mostly the names of objects. It is believed that by school age, children know between 8,000 and 14,000 words but by 18 years old, a person probably knows around 80,000 words. Researchers agree that all children go through a word spurt, although there is individual variation in when this begins (Benedict, 1979; Mervis & Bertrand, 1994).

For a concise overview of the key developmental stages of language acquisition, please see table.

Source: University of Derby (2023)