Vocabulary development
[6] Infants must be able to hear and play with sounds in their environment, and to break up various phonetic units to discover words and their related meanings.
Studies related to vocabulary development show that children's language competence depends upon their ability to hear sounds during infancy.
Babbling is an important aspect of vocabulary development in infants, since it appears to help practice producing speech sounds.
The phonemes and syllabic patterns produced by infants begin to be distinctive to particular languages during this period (e.g., increased nasal stops in French and Japanese babies) though most of their sounds are similar.
By the age of eighteen months, children typically attain a vocabulary of 50 words in production, and between two and three times greater in comprehension.
[14] In word learning, the mapping problem refers to the question of how infants attach the forms of language to the things that they experience in the world.
[16] Many theories have been proposed to account for the way in which the language learner successfully maps words onto the correct objects, concepts, and actions.
[18] Yet other theorists have proposed social pragmatic accounts, which stress the role of caregivers in guiding infants through the word learning process.
[20][21] Recently, an emergentist coalition model has also been proposed to suggest that word learning cannot be fully attributed to a single factor.
[1] Theories of word-learning constraints argue for biases or default assumptions that guide the infant through the word learning process.
[18] Children are thought to notice the objects, actions, or events that are most salient in context, and then to associate them with the words that are most frequently used in their presence.
[23] Domain-general views have been criticized for not fully explaining how children manage to avoid mapping errors when there are numerous possible referents to which objects, actions, or events might point.
[19] Cues such as the caregiver's gaze, body language, gesture, and smile help infants to understand the meanings of words.
[19] Social pragmatic theories stress the role of the caregiver in talking about objects, actions, or events that the infant is already focused-in upon.
[33] As well, conversational co-presence is likely to occur; the caregiver and child typically talk together about whatever is taking place at their locus of joint attention.
[33] Social pragmatic perspectives often present children as covariation detectors, who simply associate the words that they hear with whatever they are attending to in the world at the same time.
For instance, caregivers among the Kaluli, a group of indigenous peoples living in New Guinea, rarely provide labels in the context of their referents.
[38] According to its proponents, the emergentist coalition model incorporates constraints/principles, but argues for the development and change in these principles over time, while simultaneously taking into consideration social aspects of word learning alongside other cues, such as salience.
[41] They have flexible and powerful social-cognitive skills that allow them to understand the communicative intentions of others in a wide variety of interactive situations.
Children ages one to three often rely on general purpose deictic words such as "here", "that" or "look" accompanied by a gesture, which is most often pointing, to pick out specific objects.
Children use a small number of general purpose verbs, such as "do" and "make" for a large variety of actions because their resources are limited.
[46] When giving and responding to feedback, preschoolers are inconsistent, but around the age of six, children can mark corrections with phrases and head nods to indicate their continued attention.
Caregivers may model the appropriate behaviour, using verbal reinforcement, posing a hypothetical situation, addressing children's comments, or evaluating another person.
Peer interaction provides children with a different experience filled with special humour, disagreements and conversational topics.
These pragmatic directions provide children with essential information about language, allowing them to make inferences about possible meanings for unfamiliar words.
[65] This may be done using illustrations in the book to guide explanation and provide a visual reference or comparisons, usually to prior knowledge and past experiences.
When engaging in play with an adult, a child's vocabulary is developed through discussion of the toys, such as naming the object (e.g. "dinosaur") or labeling it with the use of a rare word (e.g., stegosaurus).
Calling upon prior knowledge is used not only in conversation, but often in book reading as well to help explain what is happening in a story by relating it back to the child's own experiences.
[63][73] By the time children are in school, they are active participants in conversation, so they are very capable and willing to ask questions when they do not understand a word or concept.
[75] As lexical knowledge increases, phonological representations have to become more precise to determine the differences between similar sound words (i.e. "calm", "come").
