As children develop their phonological system, they de-
velop an internal representation of each phoneme in their native language, which is important to differentiate minimal pairs. In essence, a phonological representation
is a neurological imprint of a phoneme that differentiates it from other phonemes. Having this imprint (internal representation) does not necessarily correspond to being able to produce a phoneme, as we can see here in this exchange between the second author and her 3-year-old son, Griffin:
Griffin: We need to “sine” the mirror.
LJ: Sign the mirror?
Griffin: No, we need to “sign” it. (emphasizes the initial /s/)

This exchange implies that Griffin has an internal representation of the “sh” sound (the initial phoneme in shine), and perceives the meaningful difference in the minimal pairs shine and sign; however, his production does not match that internal representation. This is not an uncommon sort of exchange with children in this age range, whose internal phonological representations seem to be more
sophisticated than their expressive capabilities (at least for certain sounds, such as
“sh” and “th”).

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Phonological development

Phonological development also involves developing sensitivity to the phonotactic rules of a person’s native language; these rules specify “legal” (i.e., acceptable)
orders of sounds in syllables and words and the places where specific phonemes can and cannot occur. Early in development, children become sensitive to both. For example, they recognize that /l/ + /h/ is an illegal combination of sounds in
English, and that /t/ + /s/ is legal in the final position of a syllable (e.g., pots) but
illegal in the initial position.

Phonological Building Blocks

Phonological Building Blocks
Phonological development begins immediately after birth (if not before) as the in- fant experiences speech in the environment.

Cues to Segment Streams of Speech

Cues to Segment Streams of Speech
One of the earliest phonological tasks infants face is parsing the streams of speech occurring in the world around them. Early in development, infants exhibit the capacity to use specific cues within the speech stream to parse it into smaller units (e.g., words) and to separate simultaneously occurring speech streams (e.g., the
speech on the television vs. the mother’s speech; Hollich, Newman, & Jusczyk, 2005). One strategy infants use to parse speech streams is to draw on prosodic and phonotactic cues (Estes, 2014; Gerken & Aslin, 2005).

prosodic cues

When using prosodic cues, infants draw on their familiarity with word and syllable stress patterns, or the rhythm of language, to break into the speech stream. For example, infants exposed to English rapidly become sensitive to prevalent stress patterns in English words, including the strong–weak stress pattern
in such words as little and grammar (Thiessen & Saffran, 2003

During the first year of life, infants use their knowledge of predominant word-stress patterns to locate boundaries between words in running streams of speech. For example,
they presume that a word boundary occurs following two syllables of a strong– weak stress pattern, given the prevalence of this word-stress pattern in English. For the infant who hears “little boy,” this cueing strategy helps him to isolate little and boy as separate words. Infants also recognize relatively early that pauses of-
ten occur at the boundaries between clauses and phrases (Gerken & Aslin, 2005; Hawthorne & Gerken, 2014). Infants’ sensitivity to the way in which pausing marks linguistic boundaries within speech streams, such as clause segments, may support their syntactic development because it provides the opportunity to analyze how smaller syntactic units combine to form larger units of speech

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phonotactic cues

Infants also use phonotactic cues to parse the speech stream. Early in development, infants become sensitive to the probability that certain sounds will occur both in general and in specific positions of syllables and words (Jusczyk, Luce, &
Charles-Luce, 1994).

Thus, when encountering a speech stream containing the pho-
neme sequence /gz/, the English-learning infant recognizes the improbability that this sequence starts a word. In contrast, this sequence is both legal and probable in the final position of a word (dogs, eggs), and he or she uses knowledge of these
probabilities to segment a likely word boundary following the sequence. Knowledge of phonotactic probabilities and improbabilities is an important tool for the infant to use to segment novel words from a continuous speech stream (Estes, 2014).

Phonemic Inventory

Phonemic Inventory
Another major building block in phonological development is the child’s acquisition of internal representations of the phonemes composing his or her native language—termed phonological knowledge—and his or her expression of these
phonemes to produce syllables and words—termed phonological production or expression.

Children develop a full phonemic inventory gradually as they make
more and more fine-tuned distinctions among phonemes. When their inventory is
relatively small, children use a single phoneme (e.g., /d/) to express multiple pho-
nemes (e.g., /t/, /d/, /k/, and /g/). This means a 2-year-old might say both “take”
and “cake” as “dake.” Children gradually add more phonemes until their inventory
is complete and adultlike.

The child’s phonemic inventory includes both vowels and consonants.

Vowels develop prior to consonants, typically in the first year of life. In contrast, not all consonants are acquired or expressed at the same time; some emerge early in development (early consonants) and others emerge later (late consonants)

.,

Several factors influence the timing of development for specific phonemes, including the phoneme’s frequency of occurrence in spoken language, the number of words
a child uses that contain a given phoneme, and, to some extent, the articulatory complexity of producing the phoneme (Amayreh, 2003; To, Cheung, & McLeod,
2013). Because of these influences, the order of consonantal acquisition varies among languages; for example, English-speaking children master /z/ earlier than Arabic-speaking children because this phoneme occurs more frequently in English
than in Arabic (Amayreh, 2003).

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In general, children’s phonological knowledge and production are sufficiently well developed by age 3–4 years to provide for fully intelligible speech. Although some consonantal phonemes will elude mastery for several more years, the child’s inventory is large enough to allow reasonable substitutions of mastered phonemes
for those yet to be mastered (e.g., /d/ for the initial sound in that). Figure 2.1 pro- vides a summary of the order of mastery for the English consonantal phonemes. Examining this figure, note that an early-emerging phoneme is /m/ and a later emerging phoneme is /v/. Why do you think /m/ would emerge early and /v/ later
among English-speaking children?

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Phonological Awareness

Phonological Awareness
Phonological awareness is an individual’s ability to attend to the phonological units of speech through implicit or explicit analysis. We can examine an individual’s phonological awareness using a variety of simple oral tasks (so the individual com-
pleting the tasks must listen to the phonological units and not read them):

Syllable counting: How many syllables are in the word psychologist? (Answer: four)
2. Rhyme detection: Of these four words, which two rhyme: four, boat, hat, door? (Answer: four, door)
3. Initial sound identification: What is the first sound in the word boat? (Answer: /b/)
4. Initial sound elision: Say the word boat without the /b/. (Answer: oat)
5. Phoneme counting: How many sounds are in the word justice? (Answer: six)

All of these tasks require an individual to attend to the phonological units of words, ranging from fairly large units (syllables, item 1) to the smallest units (each individual phoneme, item 5). Of the five tasks, the latter three are the most chal- lenging because one has to attend to the smallest units of phonology by identifying or eliding the first sounds in words (items 3, 4, and 5), or by counting all of
the phonemes in a word (item 5). When an individual is able to attend explicitly to the individual phonemes in words, as is necessary for task 5, he or she is said

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phonemic awareness

to have phonemic awareness (awareness of the individual phonemes of a language). Although young children demonstrate phonological awareness as early as
2 years, which is apparent in their ability to produce rhyming patterns and engage in word play (e.g., “Lily-Lily-bo-Billy . . . ”), children typically do not exhibit phone-
mic awareness until several years later (Anthony et al., 2011).

Phonological awareness provides an important bridge between language de- velopment and reading achievement (Melby-Lervåg, Lyster, & Hulme, 2012). This
is particularly true for alphabetic languages, such as English, in which the written script represents phonemes using letter-to-sound pairings for individual letters (B = /b/) and letter sequences (e.g., OUGH = /o/). Phonics instruction teaches children the relationships between letters and sounds, and children who are “phonologically
aware” can better profit from phonics instruction than children who are unaware
(see Metsala & Ehri, 201

Many children in the United States struggle to develop
basic word-reading skills, and for many of these children, a contributor to this struggle is underdeveloped phonological awareness (Fuchs et al., 2012). Systematically teaching children to attend to the phonological structure of language, through the use of games and other similar activities, is an important aspect of early-reading instruction that can have long-term, positive effects on future reading achievement
(Suggate, 2014).

Native Language

Native Language
Infants’ phonological development is influenced significantly by the phonemic composition of the language (or languages) to which the infants are exposed. Speech sounds that are phonemic in one language may not be phonemic in another. Thus,
children learning Arabic acquire representations of the phonemic inventory of Arabic and not the inventory of English (or any other language); for this reason, Arabic-speaking children will not develop a phonemic representation of /p/
because it is not phonemic in their language.

Even when a given speech sound is phonemic in two languages, children may acquire it at different times, depending on the frequency with which it appears in words and its similarity to other phonemes in the language inventory. In othernwords, the functional load of a phoneme can vary among languages.

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Functional load

Functional
load refers essentially to the importance of a phoneme in the phonemic inventory of the language, which corresponds to the volume of words that are distinguishable by that phoneme (Wedel, Kaplan, & Jackson, 2013). If we draw again on the comparison of English and Arabic, English-speaking children master /z/ by about
age 4 years (Grunwell, 1997), whereas Arabic-speaking children do not master this phoneme until after age 6 years (Amayreh, 2003). In English, the phoneme /z/ has
a high functional load, in part because it is used for pluralization (e.g., vans, dogs),
whereas in Arabic it has a low functional load (Amayreh, 2003).

Linguistic Experience

Linguistic Experience
Even among children who are learning the same language, differences exist in the timing of their establishment of phonological representations and in their production of different phonemes (McCune & Vihman, 2001). Children develop
phonological representations through their exposure to phonemic contrasts in their language; thus, differences in the timing of phonological development occur, at least in part, because of variability in children’s phonological exposure. The internal phonological representations of children reared in lower-income homes can be less
mature and distinct than those of children of the same age reared in higher-income homes, probably because of variations in the children’s exposure to language (Mc- Dowell, Lonigan, & Goldstein, 2007). The same holds true for children with a history of chronic ear infections, whose phonological representations are less mature than those of children without such a history (Haapala et al., 2014). This is because
children with chronic ear infections experience periods in which linguistic expo- sure is compromised.

What is Morphological Development

What is Morphological Development?
Children’s morphological development is their internalization of the rules of language that govern word structure. Morphemes are the smallest meaningful units of language, and many words include several morphemes. Morphemes allow the grammatical inflection of words, as in adding -ed to walk to create the past tense
verb walked, and they can change the syntactic class of words, as in adding -like to the noun child to create the adjective childlike. Morphological development thus provides children with the tools for grammatical inflection, as well as a means for
expanding their vocabulary from a smaller set of root words (e.g., child) to an ex-
ponentially larger set of derived forms (e.g., childless, childlike, childish).

grammatical morphemes (also called inflectional morphemes)

grammatical morphemes include the plural -s (cat–cats),
the possessive ’s (mom–mom’s), the past tense -ed (walk–walked), present progressive -ing (do–doing), to name a few.

Derivational morphemes

Derivational morphemes change a
word’s syntactic class and semantic meaning. For example, taking the word like, we
can add both prefixes (dislike, unlike) and suffixes (liken, likeable, likeness) to vary
its meaning and syntactic role in a sentence.

Grammatical Morphemes

Grammatical Morphemes
Children’s earliest words and sentences contain few grammatical morphemes, but only for the first year or two. At about age 2 years, children begin to use the first- appearing grammatical morpheme, the present progressive -ing. Whereas before then, the child might ask, “Where Mommy go?”, he or she now asks, “Where Mommy going?” In subsequent chapters, we discuss in more detail the child’s
timing and course of acquisition for learning the major grammatical morphemes, which include not only the present progressive -ing, but also the plural -s, the possessive ’s, and the past tense -ed, as shown in Table 2.1. Note that the grammatical morphemes in Table 2.1 include not only suffixes, but also several free
morphemes.

Suffixes (and prefixes) are called bound morphemes because they
must be bound or attached to other morphemes

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In contrast, free morphemes can
stand alone; they include both words with clear semantic referents (e.g., dream, dog, walk), and words that serve primarily grammatical purposes (e.g., his, the, that). Children’s early achievements in grammatical morphology include acquiring not only bound morphemes but also several free morphemes that serve purely
grammatical purposes, including the prepositions in and on, and the articles the,
a, and an.

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The child’s acquisition of the major grammatical morphemes, which follows a fairly invariant course in both the order and the timing of acquisition, is a subtle, but important achievement in early childhood. Although parents do not often applaud (or possibly even notice) when their children first begin to inflect verbs
for past tense, grammatical morphology enables the child to move from speaking
with a “telegraphic quality” (e.g., “Baby no eat”), to a more adultlike quality (“The baby’s not eating”). And, although parents often seem to coach their children to use new important words (as in “Say ‘bottle’!” and “Say ‘mama’!”), they don’t seem to do the same for grammatical morphemes (“Add s to ‘bottle’!”). However, and
perhaps thankfully so, parents don’t need to coach their children to use grammatical morphemes at all, as children figure out the rules for when to use them, even at
very young ages (Zapf & Smith, 2007)

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When researchers study children’s grammatical morphology, they often examine obligatory contexts of use, and determine whether the child has omitted or included the obligatory morpheme.

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obligatory context occurs

An obligatory context occurs when a mature
grammar specifies the use of a grammatical marker; for instance, in the phrase The girl’s house, the possessive ’s is considered obligatory. Thus, if a child says “The girl house,” he or she is omitting the possessive (’s) morpheme in an obligatory context.
As another example, if a child says “two baby,” he or she is omitting the plural (s) in an obligatory context. When children include a grammatical morpheme in 75% o

Derivational Morphemes

We add derivational morphemes to root words to create derived words. The corpus of words derived from a common root word (e.g., friend, friendless, friendliness, befriend) share derivational relations. We can create derived words by attaching
morphemes, both prefixes and suffixes, to root words to yield polysyllabic words (words containing more than one syllable). Table 2.2 presents some commoprefixes and suffixes used for derivational purposes. Because each prefix and suffix
can be combined with many root words, derivational morphology is a powerful
tool for adding precision to a person’s lexical base.

Influences on Morphological Development

Influences on Morphological Development
One of the seminal works of child language research is Roger Brown’s (1973) book, A First Language. In this key work, Brown carefully described children’s development of 14 grammatical morphemes, showing how a core of grammatical morphemes emerged in a uniform order among children (see Research Paradigms:
Longitudinal Studies). These morphemes appear in Table 2.1. Brown’s work had a tremendous influence on the field of child language research, prompting many researchers to focus on describing other such universalities in child language
development

Since then, researchers have begun to appreciate the importance of studying individual differences in language acquisition, and identifying specific influences that do and do not affect the normal course of language acquisition. For example, researchers have questioned whether a child’s native language influences his or
her development of grammatical morphology. Contrary to what you might expect, children learning languages that are richly inflected (e.g., Spanish) do not acquire novel morphemes at faster rates than those of children learning less richly inflected
languages (e.g., English).

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Second Language Acquisition
Persons learning a second language that differs considerably in its grammatical morphology from their native language may never master the grammatical morphology of the second language (Bialystok & Miller, 1999; Jia, Aaronson, & Wu,
2002). For instance, native Chinese speakers who learn English as a second language find the plural marker difficult to master because plurality is not inflected morphologically in the Chinese language (Jia, 2003). This is particularly true when persons learn a second language at an older age rather than at a younger age, or
when a specific morpheme is not inflected in a person’s native language. However, even for younger children, learning the grammatical morphology of a second language can be challenging. Jia’s (2003) longitudinal study of 10 Chinese-speaking
children during a 5-year period focused on the acquisition of the plural -s, which is not grammatically inflected in Chinese. Three of the 10 children, even after 5 years’ immersion in English, never mastered the plural morpheme, and those who did so were usually younger at their initial immersion in English. The three children who did not master the plural morpheme used it in fewer than 80% of obligatory con-
texts, typically omitting the plural marker.

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Dialect

Dialects are the variants of a single language. The dialects of a language vary in a
number of important ways from the “general dialect,” including their morphology.

Even among speakers of a single language (e.g., English), achievement of specific morphological building blocks can vary substantially as a function of the morpho-
logical features of the dialect the speakers are acquiring. In the United States, one dialect many speakers share is African American English (AAE). Some morpho- logical features of AAE differ from those of General American English (GAE), including the use of copulative, or be, auxiliary verbs; verb tense inflections; and possessive and plural inflections (Charity, Scarborough, & Griffin, 2004). For in-
stance, a GAE speaker may say, “Tom’s aunt,” whereas an AAE speaker may say, “Tom aunt,” omitting the possessive marker. Some children learn only the AAE dialect, whereas others learn the AAE dialect before, while, or after learning the GAE dialect. AAE-speaking students who have more knowledge of GAE tend to perform
better in reading development, possibly because less of a mismatch occurs between the written form of language they encounter in school (which uses GAE) and the
dialect they speak (Charity et al., 2004).

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At least in part, the mismatch between AAE
and GAE involves differences in morphology, particularly grammatical inflections. Alternatively, it may also be that AAE-speaking students who have more knowledge of GAE have a strong capability to code-switch; that is, to switch between their two dialects (Connor & Craig, 2006; Craig, Zhang, Hensel, & Quinn, 2009). Children
who can readily switch between dialects may have a heightened meta-linguistic awareness, which can support reading development. In this regard, there may be benefits to helping children acquire the ability to switch between dialects, with a focus on helping children understand the value of their own dialect and the value
of learning the dialect used in schooling.

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Language Impairment
Language impairment affects morphological development, often in significant ways. In fact, one hallmark of specific language impairment (SLI), a developmental language disorder we mentioned in Chapter 1 and discuss more thoroughly in Chapter 10,
is difficulty with grammatical morphology. For instance, whereas typically developing children use the present progressive -ing with more than 80% accuracy, children
with SLI use it with only 25% accuracy (Conti-Ramsden & Jones, 1997). In general, children with SLI seem to have very specific difficulties with verb tense markings,
such as the past tense inflection and the third-person singular inflection (e.g., He
runs.).

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What is Syntactic Development?
Syntactic development is children’s internalization of the rules of language that govern how words are organized into sentences. As Pinker (1994) stated in his seminal work on language acquisition, The Language Instinct,

When a dog bites a man that is not news, but when a man bites a dog that is news.
. . . The streams of words called “sentences” . . . tell you who in fact did what to
whom. (p. 83)

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