Handbook of Language and Literacy Development - a Roadmap from 0 to 60 Months

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Introduction to Speaking 13 - 24 Months - Towards Word Combinationsclick to print Print
Research Review / Parent

Written by: Carrie Gotzke and Heather Sample Gosse, University of Alberta

In the 13 to 24 month period, toddlers continue to produce babbling, jargon and protowords. During this time, the size of toddlers' expressive vocabularies increases from 1 to 100 hundred words. They also begin to produce two-word combinations. Toddlers use their growing vocabularies to label objects and to interact socially. Speaking continues to develop in the context of interaction with others. For information on this critical context, please refer to Interacting.

Vocalizations - Increasing Control of Sounds

Even after they are producing real words, twelve- to twenty-four-month-old toddlers continue to produce babbling, jargon and protowords. These early vocalizations remain important ways in which toddlers develop control over their vocal mechanism and sound production. Toddlers demonstrate this increased control by manipulating pitch and intonation. For more information on jargon and protowords, please refer to Vocalizing 10 - 12 months.

Babbling

In the 13- to 24-month period, toddlers continue to babble as they develop increasing voluntary control over early speech sounds. Around 12 to 13 months, variegated babbling (e.g., bagidabu) becomes more common than reduplicated babbling (e.g., bababa) (Menn & Stoel-Gammon, 2005). Consonants produced during babbling for English-speaking toddlers include stops /p, b, t, d, k, g/, nasals /m, n/, glides /w, j/ and fricatives /sh, h/ (Menn & Stoel-Gammon, 2005). These 12 consonants account for 95% of the consonants produced during this time and tend to predominate in the first adult-based words. Sounds not produced during babbling (e.g., liquids / l, r/, fricatives /v, th/ and affricates /ch, j/) generally do not appear in early words. However, there may be individual variation.

Sound production during babbling is influenced by the environmental language. For example, toddlers exposed to Mayan may produce /l/ during babbling, whereas toddlers exposed to English may not (Menn & Stoel-Gammon, 2005). Some toddlers will continue babbling even after they begin producing words, while others may have a silent period between babbling and word production.

Pitch

During the second year, toddlers increasingly use pitch to help convey meaning (Owens, 2001). Toddlers first develop a flat or falling contour which is used for naming or labeling. Between 13 and 15 months, toddlers develop a rising intonation pattern. This contour is used for requesting, attention getting and expressing interest. Around the same time, toddlers also develop a high falling contour in which they start the utterance at a high pitch and drop to a lower one. This intonation is used to convey surprise, recognition, insistence, and greeting. High rising and high rising-falling contours develop next to express anticipation and stress respectively. At 18 months, toddlers begin to use a falling-rising contour for warning and a rising-falling contour in play. In conversation, twenty-four-month-old toddlers will use specific pitch patterns for different intentions, but do not use these patterns when talking to themselves.

Speaking - From the First Word to Ever-Increasing Vocabularies

By the end of the first year, many toddlers have produced their first word (Owens, 2001; Sachs, 2005). However, it is not unusual for toddlers to produce their first word around 15 months of age. Over the course of the second year, toddlers will develop an expressive vocabulary of over 100 words. There are multiple factors influencing toddlers' vocabulary choices including their sound repertoire, word complexity and caregiver speech.

Characteristics of the Early Words

Early words generally serve a social purpose, contain a limited number of different consonants and have simple structures. Despite these similarities, there is a great deal of variation among toddlers in terms of the pattern and rate of vocabulary growth, use of protowords and syllable structures produced (Owens, 2001).

Characteristics of the Early Words

First words tend to be similar for toddlers across cultures (Pan, 2005). Generally, toddlers first learn words that serve social purposes, known as performatives (Owens, 2001). These first words may include the name of a toy, food or family member (Owens, 2001) or a greeting, farewell or other social phrase such as peek-a-boo (Menn & Stoel-Gammon, 2005). These words may gradually replace or augment social gestures (e.g., saying "hi" in place of waving). Toddlers' first words serve the same functions as the gestures and vocalizations they used in the previous six months. Words are used by toddlers to name objects or people and to gain attention or some object. Names for animals, toys and foods are the most frequent words in the first ten words.

Early words used by toddlers may be onomatopoeic, imitating or suggesting the object it describes (e.g., "woof-woof" for dog) (Pan, 2005). Gradually, toddlers learn the adult or symbolic word for these objects. By 21 months, vocabularies may contain sound effects and names for food, drinks, animals, body parts, clothing, people, toys, and vehicles (Pan, 2005). Words for actions, games and routines, as well as adjectives, may also be produced. Sometimes early words are actually approximations of frequently used adult phrases (Owens, 2001). For example, toddlers may say "anku" for "thank you." Typically the vocabulary of toddlers in the second year includes a few progressive phonological idioms (i.e., words similar to adult forms; e.g., hi) as well a few variable and inaccurate protowords (i.e., vocalizations used at appropriate times and with consistent structures that do not resemble the adult model; e.g., "bini" for blanket) (Menn & Stoel-Gammon, 2005).

Types of Words

Toddlers use predominantly content or open-class words (i.e., nouns, verbs, adjectives) in their utterances (Tager-Flusberg, 2005). Most frequently, toddlers' early vocabulary is composed of nouns that refer to persons or objects in their environment (Owens, 2001). Known as substantive words, they refer to a specific object or group of objects with similar perceptual or functional features. Toddlers generally do not have nouns that refer to groups (e.g., forest) or abstractions (e.g., joy) in their early vocabularies. Nouns account for 60 to 65% of all words in toddlers' first 50 words, whereas action words account for fewer than 20%. The proportion of nouns decreases and the proportion of verbs increases once toddlers' vocabulary reaches 100 words. One explanation for the predominance of nouns in toddlers' vocabulary may be related to the frequency with which nouns are used in caregiver speech. Caregivers more frequently label objects than actions, properties or relations (Pan, 2005). Toddlers may produce more nouns because they are less linguistically complex, as well as more concrete and identifiable than verbs.

Initially, verbs used by toddlers are protoverbs (Owens, 2001). Protoverbs accompany actions of putting objects together or taking them apart and may include in, out, and off. Toddlers may also use greetings such as bye-bye and nouns such as ni-night in verb-like ways. Following the development of protowords, toddlers begin using general-purpose action words such as do and make as well as other types of action words. Toddlers use deicitic action words (e.g., lookit) to direct their communication partner's attention and require that their partner take their point of view. Action-specific verbs used by toddlers include object-related and intransitive words. Object-related action-specific verbs refer to specific actions performed on objects (e.g., push), while intransitive action-specific verbs refer to specific non-object-related actions (e.g., walk). As verbs can be used with different nouns to convey a variety of messages, toddlers may use fewer verbs (Hoff, 2001). Furthermore, in order to use a verb appropriately, toddlers must first understand different aspects of the verb's meaning (Pan, 2005). The linguistic and conceptual complexity of verbs may first lead toddlers to use general verbs such as do, go or make.

Toddlers seem to learn nouns and verbs differently (Owens, 2001). Toddlers learn nouns while simultaneously looking at both the object and their caregivers, which is generally not possible for verbs. Between 15 and 21 months, verb-learning is facilitated when caregivers first say the verb and then follow it with the action. Performing the action and then saying the word has also been found to be an effective strategy for facilitating verb learning.

Toddlers rarely use closed-class words such as prepositions, conjunctions, articles, pronouns and auxiliaries in their utterances. As a result, toddler utterances during this time are often referred to as telegraphic as closed-class words are omitted similar to written telegrams. Toddlers may learn open-class words (i.e., nouns, verbs, adjectives) earlier due to their perceptual salience.

There are differences in the order of acquisition of open- and closed-class words among toddlers learning different languages. Toddlers learning Italian or Hebrew may acquire closed-class words earlier. Toddlers learning Mandarin may learn verbs at the same time as nouns.

Phonology

Generally, first words match babbling patterns in terms of speech sounds. Word acquisition begins with a trial-and-error approach to single words (Menn & Stoel-Gammon, 2005). Initially, toddlers' words are all phonetic approximants of adult words (Owens, 2001). They are identifiable as words as they are consistently used by the toddler to refer to a particular object or situation. Gradually, some words may come to match the adult form quite well (eg., "i" for hi), whereas others may remain approximations of the adult form (e.g., "ees" for cheese). Researchers have found that words that are easier to pronounce are more likely to be found in early vocabularies (Pan, 2005).

Sounds most frequently found in toddlers' first words include stops /p, b, t, d, k, g/, and /h/ (Owens, 2001; Apel & Masterson, 2001). Occasionally, nasals /m, n/ and fricatives /f, s/ may be produced. The exact order and age of acquisition of sounds varies across children. Toddlers may develop sound preferences which guide their vocabulary choices. These preferences are highly individual (Pan, 2005).

First words rarely, if ever, contain consonant clusters (e.g., tr or sl). If a developing word does contain a consonant cluster, toddlers have a variety of strategies for simplifying the sound structure of the word. Most toddlers will omit the first consonant from the cluster during their production (Menn & Stoel-Gammon, 2005; e.g. "pill" for "spill"). About 10% of toddlers will omit the stop consonant (e.g., "sool" for "school"). Other toddlers may omit one of the sounds (e.g., "tuk" for "truck"), while still others may insert a vowel in the middle of the cluster (e.g., "buloo" for "blue").

Toddlers' developing motor control may be one reason why some sounds are more frequently produced compared to others (Menn & Stoel-Gammon, 2005, Apel & Masterson, 2001). For example, stops are considered easier to produce as the tongue must only make contact with another articulator for correct production. In comparison, for production of fricatives, the tongue must be maintained at a certain distance from another articulator, an action which requires finer motor control.

Another possible explanation why certain sounds are produced early in comparison to others is related to perception. Some sounds are acoustically more similar than others (for example, /s/ and /sh/). Toddlers may be willing to temporarily produce the same sound for both due to their perceptual similarities. It has been suggested that toddlers who produce certain sounds incorrectly may also have difficulty perceiving them (Menn & Stoel-Gammon, 2005). However, as toddlers have the same discrimination skills as adults, production appears to be unrelated to perception.

Caregivers may facilitate their toddlers' speech sound and vocabulary development through changing their own speaking patterns. Researchers have found that caregivers clarify their pronunciation of stops for their children at the one-word stage but not when they were prelingual or for adults (Menn & Stoel-Gammon, 2005). Similarly, researchers have found that caregivers will clarify vowel production by modeling for nouns, verbs and adjectives only.

Structure

First words are generally one to two syllables in length (Owens, 2001). The syllable shape of these words may be vowel-consonant (e.g., bye), consonant-vowel (e.g., up) or consonant-vowel-consonant-vowel (e.g., puppy). Toddlers may also produce consonant-vowel-consonant words but most often will modify their syllable structure. For example, toddlers may delete the final consonant (e.g., producing "hat" as "ha") or add a vowel sound following the final consonant (e.g., producing "hat" as "hat-a"). Over time, toddlers become able to produce contrasting consonants in CVC words (e.g., cup). In the case of CVCV words, toddlers tend to produce the same consonant sound in both positions even in words where in adult productions these are different sounds (e.g. producing "dawdie" for "doggie"). It is interesting to note that although toddlers will produce the same consonant sound in both positions in CVCV words, they will produce different vowels within a two syllable word correctly (see previous example). Sometimes toddlers will omit the unstressed syllable in CVCV words. This omission may occur because unstressed syllables are harder to perceive (Menn & Stoel-Gammon, 2005).

Initially toddlers may select words for production based on the syllable shape, length and sounds found in an individual word, choosing words with simple shape that contain sounds they can produce (Menn & Stoel-Gammon, 2005, Owens, 2001). Toddlers may avoid producing words that contain sounds or sound sequences that are not in their repertoire. For example, toddlers living in an English-speaking environment are not likely to produce "fish" correctly, as /f/ is a late-developing sound. When toddlers attempt words that contain these late-developing sounds, they may produce the word using sounds that are in their repertoire (e.g., "pi" for "fish"). Generally by two years of age, their vocabulary choices will no longer be limited by their ability to produce sounds.

Influences on Vocabulary Choices

Toddlers' vocabulary choices are guided by five factors: environment, word type, sounds in the word, usefulness, and style (Apel & Masterson, 2001). Toddlers learn words they hear, therefore, frequency of caregiver use may influence which words toddlers produce. In terms of word type, toddlers tend to learn concrete (e.g., dog) rather than abstract words (e.g., joy). For information on the role of sound and word structures in vocabulary choices, see phonology and structure of words. With respect to the fourth factor, toddlers may produce words that are more useful to them before others. For example, toddlers may say sock before shirt because they are able to put on their socks before their shirts.

Finally, word production may be guided by personal style. Some toddlers prefer to label objects and people and have word structure and sound preferences which guide the words they attempt to produce. These toddlers are referred to as having a referential style (Owens, 2001; Apel & Masterson, 2001). They tend to interact more with adults, use more single words and follow a bottom-up strategy in which they gradually build longer utterances from single words. For toddlers with a referential style, labeling, imitating and describing by caregivers are beneficial to language learning.

Other toddlers have an expressive style. These children are considered risk-takers as they produce words regardless of whether they are able to produce them accurately or not. Toddlers with an expressive style tend to use fewer nouns and more interactional words (e.g., hi), functional words and unanalyzed wholes (e.g., allgone). These toddlers tend to interact more with peers, attempt to produce longer utterances and use a top-down approach to learning language by breaking longer utterances into single words. Conversation and paralinguistic modifications appear to provide important learning opportunities for referential language learners.

Meanings of Words Used

From 13- to 16-months, each word-like vocalization has a specific meaning and is used by the toddler only to express that function (Hoff, 2001; Owens, 2001). For example, toddlers may use more to request but not to indicate when there are multiple items (i.e., recurrence). By 24 months, toddlers can use the same vocalization or word more flexibly to express a variety of functions. It is important to note however, that some words have the same meaning for toddlers as adults from the first time they are used.

Most frequently, toddlers in the second year are using their developing vocabulary to label objects and to interact socially (Tager-Flusberg, 2005). Toddlers will use words in the same context as they were originally heard (e.g., saying "bye-bye" while waving), while others will be used for naming and labeling. To determine if they are using a word correctly, toddlers watch their caregivers' responses. Caregivers use the ongoing activity, as well as the toddler's nonlinguistic behaviors, to interpret their toddler's utterances (Owens, 2001).

An important part of early word learning is developing the understanding that words refer to a whole class of similar objects or a category not just a single referent (Pan, 2005). Initially, toddlers may use a label to refer to a single referent (Hoff, 2001; Owens, 2001; Pan 2005). For example, a toddler may call the family pet "doggie" but will not call any other dogs in the neighbourhood or pictures of dogs "doggie." Labels restricted to a specific referent or concept are referred to as underextensions. Underextensions are common in both receptive and expressive language. Within a month of acquisition, words that were underextended will be generalized to multiple referents. Underextensions are more common during early word learning.

Toddlers may also use a label to refer to multiple referents, extending its meaning beyond that of adults (Hoff, 2001; Owens, 2001; Pan 2005). For example, toddlers may call all animals with four legs "horsie." This broadening of word meaning is referred to as overextension. Overextension is common during the period of rapid vocabulary growth that occurs prior to the production of two-word utterances. About 30% of words in toddlers' 75-word vocabulary are overextended. Letters, vehicles and clothing categories are more frequently overextended than other word categories. While toddlers may overextend productively, their comprehension is adult-like. With continued experience in and exposure to language, toddlers use fewer underextensions and overextensions.

Overextensions and underextensions are considered to be evidence that toddlers may have different underlying word concepts than adults (Pan, 2005). However, there may be other explanations for their occurrence. Overextensions may occur because toddlers are unable to retrieve the correct label from their meaning. Alternately, they may not yet know the correct label for the object (Hoff, 2001; Pan, 2005). Toddlers may also be using overextensions to comment on similarities between objects or as a joke.

Toddlers receive both implicit and explicit feedback about how accurately they are using words (Owens, 2001). Implicit feedback occurs when toddlers listen to how other speakers use labels. Caregivers provide explicit feedback in the form of direct correction or confirmation. Caregivers may also demonstrate to their toddlers why a particular referent belongs to a category (e.g., saying "This is a bird because it has wings and a beak and it flies.").

Vocabulary Growth

Vocabulary growth is slow in the first few months after the appearance of the first word (Owens, 2001). During this time, toddler speech consists primarily of jargon and single words. Three months after the appearance of the first words, toddlers may have a four- to six-word vocabulary. It is important to remember that although they may be producing only a few words, toddlers understand many more words than they can produce. Maternal reports suggest that 16-month-old toddlers comprehend between 100-200 words but produce fewer than 50 (Pan, 2005). However, expressive vocabularies between 1 to 160 words at 16 months of age are considered to be within the normal range (Owens, 2001). Once they have produced their first word, researchers have determined that toddlers acquire an average of eight to eleven words to their vocabularies each month from 13 to 18 months (Hoff, 2001).

By 18 months, most toddlers have a 50 word vocabulary and produce some two-word utterances (Owens, 2001). Within this 50 word vocabulary, toddlers may have a core vocabulary of eight to ten words that are used frequently. Some of the remaining words may be used once a day, while others may be used once every few months. At this time, toddlers also begin to refer to themselves by name and may sing and hum. Eighteen-month-old toddlers continue to use words to label and to gain attention but also use words to express demands. The average rate of vocabulary growth increases to 22 to 37 words per month after toddlers have 50 words in their vocabulary (Hoff, 2001). By 21 months, toddlers begin to use I and mine.

Caregivers may note rapid growth in their toddler's vocabulary after 18 months (Owens, 2001; Tager-Flusberg, 2005). By 24 months, most toddlers will have a 200 to 300 word vocabulary. However, expressive vocabulary size may range between 50 and 550 words and still be considered to be within the average range. Twenty-four-month-old toddlers are able to name most common everyday objects and use some prepositions (i.e, in, on) and pronouns (i.e., I, me, you) although not always correctly. These toddlers also use some regular verb endings (i.e., -s, -ed, -ing) and plural -s. In addition to labeling, attention-getting and demanding, twenty-four-month-old toddlers also use their vocabulary to request, question, state, express emotions, and as accompaniments during play. They are also showing increasing interest in rhyming songs, stories and activities. In addition to showing rapid growth in productive vocabulary between 18 and 24 months, toddlers may also show rapid growth in receptive vocabulary.

Toddlers with different styles may have different rates of vocabulary growth. Toddlers with a referential style tend to show a rapid increase in vocabulary size between 14 and 18 months, while toddlers with an expressive style tend to show a more gradual increase in vocabulary size.

During the course of vocabulary growth, toddlers may seem to lose established words as they gain new ones (Hoff, 2001). The rate of vocabulary growth may be quite variable, with periods in which no new words are added. The amount of speech used by caregivers may predict the rate of toddlers' vocabulary growth.

Patterns of Word Learning

Researchers have described regression in toddler's productions of words, in which established word productions become incorrectly produced (Menn & Stoel-Gammon, 2005). This regression to earlier incorrect forms and patterns may occur as toddlers learn new words and generalize the new sound patterns to established words. For example, toddlers, who substitute /f/ for /s/, will, upon learning /s/, replace /f/ with /s/ in all words, even those in which /f/ is the correct sound. Regression has also been noted as toddlers try to use established sounds in new words. Toddlers may omit an established sound when first trying it in new words. For example, a toddler may be able to produce "hi" correctly but when learning other words that start with /h/ may initially produce them without /h/ (e.g., producing "hat" as "at"). This may occur even though the toddler continues to use /h/ in "hi." Words that are more similar to adult forms than their other words (such as "hi") are called progressive phonological idioms.

Speaking - Combining Words

Towards the middle of the 13 to 24 month period, toddlers begin producing word combinations. These combinations increase both the variety of messages and the clarity of their communication attempts.

Transitioning to Word Combinations

Prior to using two-word utterances, toddlers may go through a transition period in which they produce sequences of words, gestures and sounds (Owens, 2001). There are different types of transitional combinations in which toddlers use a vocalization with a word. In the first type, toddlers produce a consonant-vowel syllable either before or after a word (e.g., ma baby; baby da). When toddlers use the same CV or CVCV syllable with a variety of words, this is referred to as an empty form (e.g., beda baby or doggie beda). A third form of transitional combination occurs when toddlers repeat a single utterance (e.g., doggie, doggie). The production of jargon or babble followed by a word is another type of transitional form (e.g., babagidu doggie) (Hoff, 2001).

Toddlers may produce single-word utterances that are actually composed of two words, such as all-gone or go-bye (Owens, 2001). As toddlers never use either of the two words independently nor do they use them in combination with others, they are considered single-word utterances. These types of utterances are also known as unanalyzed wholes. It appears that these utterances are learned as a single unit.

Toddlers may also produce consecutive single-word utterances (Owens, 2001). Sometimes, the successive utterances may be related to each other in meaning or build on the previous utterance (e.g., "Ow. Eye") (Hoff, 2001). Each utterance is produced with a terminal falling pitch and equal stress. There is also a pause between each word. These utterances are not considered to be word combinations as word order is more variable, unlike true combinations. Gradually, toddlers modify the pitch contour of these successive utterances to more closely resemble the contours of adult utterances. Once the pitch, pause and word order of these utterances approximate short adult speech, they are considered to be a multi-word utterance.

Timing of Word Combinations

At 18 months, most toddlers are combining words to create two-word utterances (Owens, 2001). However, there is great variability among toddlers with respect to when they begin making two-word utterances. Some toddlers may produce multiword utterances as early as fifteen months. Factors that affect when toddlers begin producing word combinations include when they produce their first word, when they understand fifty words and how responsive caregivers are to toddler communication at 12 months (Tager-Flusberg, 2005). By 24 months, the majority of toddlers are producing word combinations. As vocabulary expands, toddlers use two-word combinations more frequently.

Patterns of Word Combinations

When combining words, toddlers follow three predictable patterns (Owens, 2001; Tager-Flusberg, 2005). When toddlers use a word interchangeably either at the beginning or end of an utterance, this is called a groping pattern (e.g., eat cookie or cookie eat). In the positional associative pattern, toddlers' multiword utterances follows a consistent word order which appears to reflect adult patterns and is not self-generated (e.g., come here). The third pattern, positional productive, also has a consistent word order but the combination is generated by the toddler (e.g., Mommy do). Toddlers may learn positional rules for words through listening to adult speech. Positional productive patterns illustrate toddlers' creativity with language. There appears to be a developmental order in toddlers' use of these patterns. Toddlers' tend to use positional associative patterns before they use either groping or positional productive patterns.

Increasing Utterance Length

Once toddlers are producing equal numbers of one and two-word utterances, they begin to produce three-word utterances (Owens, 2001; Weitzman, 1992). These utterances may be one of two types: 1) recombinations of two-word utterances (e.g., "Baby eat" + "Eat cookie" becomes "Baby eat cookie") and 2) expansions of existing sentences to express attribution, possession or recurrence (e.g., Eat big cookie). The most common three-word utterances are agent + action + object (e.g., Baby color crayons) and agent + action + location (e.g., Doggie sleep yard) (Owens, 2001). Toddlers may also combine language functions within a single utterance (Owens, 2001). In the example, "Mommy cookies hot?" the toddler is requesting both information and an object. Utterances are expanded to four words in the same way as three-word utterances. Toddlers may be producing some four word utterances at 24 months of age. As toddlers' utterances increase in length, caregivers expand their toddlers' utterances less frequently (Owens, 2001).

Meanings of Word Combinations

The majority of two-word utterances used by toddlers refer to objects (Tager-Flusberg, 2005) and usually one of three types of expansions: reflexive, relational or attributive. Most initial two-word utterances are usually reflexive expansions (e.g., more milk) (Owens, 2001). In this combination, the meaning of each word remains unchanged. When reflexive expansions contain a verb, word order changes dependent on how the two words relate in terms of meaning. Reflexive expansions function to indicate recurrence (e.g., more milk) and nonexistence (e.g., no bed). Initially, recurrence is used for requesting. Nonexistence may be used to comment, request, reject or deny. Between 15 and 24 months, seventy percent of utterances serve a reflexive function.

By 21 months, most toddlers are also using relational utterances (Owens, 2001). These expansions serve to describe how objects or actions and locations relate in space. Toddlers first use the form entity + locative (e.g., doggie up) and then the form action + locative (e.g., push me). Entity + locative utterances may describe a stationary object and its location (e.g., doggie house) or a moving object and the direction of its movement (e.g., baby up). Generally, toddlers will describe stationary objects before moving ones.

Some toddlers may also begin using attributive utterances that describe physical characteristics at around 18 months (Owens, 2001). These utterances initially take the form attribute + entity (e.g., big doggie). Although toddlers may be using attributive utterances at 24 months, this form is not mastered until 30 months. Toddlers also start to produce utterances that indicate possession at around 21 months (e.g., my ball) (Owens, 2001).

Caregivers' Support for Speaking

Caregivers continue to assign meaning to toddlers' speech. Their reactions to their toddlers' speech provide feedback about the clarity of their message, which then strengthens the link between words and their meanings (Owens, 2001). Caregivers also use gestures that help their toddlers' comprehend what is being said. Eighteen-month-old toddlers use their caregivers' gaze to help interpret what is said. Caregiver intonation and emotions may also be used by toddlers to infer meaning. For example, if caregivers produce the name of a novel object with surprise, twenty-four-month-old toddlers assume that they are referring to the new object. Caregivers' responses enhance and are critically important for language development.

Once toddlers are able to use single words, caregivers may no longer accept babbling as an adequate response. After a babbled response, caregivers may request clarification (e.g., What's that?), withhold a label or repeat a question, as they attempt to elicit a word production. Caregivers may also play naming games as a way of providing opportunities for production practice (Pan, 2005).

Gotzke, C. & Sample Gosse, H. (2007). Research Narrative: Listening, Vocalizing and Interacting 13 - 24 Months. In L.M. Phillips (Ed.), Handbook of language and literacy development: A Roadmap from 0 - 60 Months. [online], pp. 1 - 8. London, ON: Canadian Language and Literacy Research Network. Available at: Handbook of language and literacy development