Language Acquisition Device

The Language Acquisition Device (LAD) is a hypothetical brain mechanism that Noam Chomsky postulated to explain human acquisition of the syntactic structure of language. This mechanism endows children with the capacity to derive the syntactic structure and rules of their native language rapidly and accurately from the impoverished input provided by adult language users. The device is comprised of a finite set of dimensions along which languages vary, which are set at different levels for different languages on the basis of language exposure. The LAD reflects Chomsky's underlying assumption that many aspects of language are universal (common to all languages and cultures) and constrained by innate core knowledge about language called Universal Grammar. This theoretical account of syntax acquisition contrasts sharply with the views of B. F. Skinner, Jean Piaget, and other cognitive and social-learning theorists who emphasize the role of experience and general knowledge and abilities in language acquisition.



Chomsky, Noam. Aspects of the Theory of Syntax. Cambridge, MA: MIT Press, 1965.

Laura L. Namy


Mike (age five years, discussing the game of baseball): Mom, did you know that baseball games need a vampire?

Mom: A vampire?

Mike: Yes, the vampire stands in back of the catcher and catches any of the balls that the catcher misses.

Joshua (age three, picking up the book Sleeping Beauty): Let's read Sleeping Buddha.

Child (age four): Nobody doesn't likes me.

Parent: You mean, "Nobody likes me."

Child: OK. Nobody doesn't likes you.

These excerpts are not mere anecdotes from three-and four-year-olds' everyday conversations. Rather, they are glimpses into the inner workings of the human mind. Language is a uniquely human behavior and is one of the most complicated behaviors in which humans engage as a species. Neither birds nor have language, and though people have spent countless hours trying to train chimps and gorillas, even they have not mastered the system. Yet, by the time children can walk, they have spoken their first words and can comprehend about fifty words. By the time children can run, they speak in full sentences and use language to control their environment and their parents. The average three-year-old has the computational power and symbolic sophistication to do what our most advanced computers cannot do—to use human language to communicate with others, and to represent things in the past, the present, and the future. The average four-year-old has mastered the complex system we call language and is fully conversant with adults and peers.

Languages as an Orchestral Work in Progress

For centuries, philosophers and psychologists have tried to understand how it is that children learn their first language. Are humans simply endowed with language? Are humans carefully taught? To address these questions one must first ask, ''What is language?'' One way of thinking about the problem is to assume that language is like an orchestra. It is composed of many parts that intricately work together to provide a unified sound. Just as there are sections in the orchestra (the strings, the brass, the wind instruments, and the percussion), there are components of language in sounds, meanings, words, grammar, and rules for how one uses each of these parts in culturally appropriate ways. Language acquisition, then, is really the development of many pieces of a language system that must evolve and work in tandem to perform the ''score'' of human talk.

The First Year: Sounds and Meanings

The journey into language begins with the sound component of the orchestra. The first piece that parents notice occurs at around three or four months when children begin to gurgle and coo. Cooing consists of series of vowel sounds that babies tend to make and that—at least American parents—respond to. Just a couple of months later, at about seven months, these same infants start to babble. The first consonant sounds (e.g., ''ba,'' ''ga'') enter into the language, and the product sounds much more like speech. In this period, children seem to carry on conversations with consonant-vowel sounds that only they can understand (e.g., ''ba ga ga ga ba ba?'').

The beginning of language, then, starts with a strong appearance from the ''sound'' component of the language orchestra. The exact role of the sound component in the development of later language, however, has been hotly debated. Is babbling, for example, a form of prespeech? Is it merely an avenue for young children to practice using their vocal chords and to imitate sounds that they hear with mouth movements that they can make? Scientists still are not sure. Yet it is interesting that even deaf children babble with sounds and that this babbling does not wane until about the point when canonical babbling comes in. Deaf children of deaf parents babble with their hands and show the same progression toward canonical babbling as do hearing children.

Even though sounds are the most dominant components of early language, the second half of the first year also represents enormous progress in how children learn to express new meanings—even before they have mastered language. Notably, by eight months of age children are quite adept at using eye gaze and grunts to indicate what they are looking at and to request an action from a parent. This pre-linguistic stage is heightened further when the child learns to point. Pointing is a specifically human gesture that dramatically increases the child's ability to communicate. At around ten months, the forefinger is used to make what some have called ''proto-declaratives'' and ''proto-imperatives''—otherwise known as statements and commands. As any parent will attest, these commands are quite direct and clear, even though the child is still technically ''prelinguis-tic.''

The Second Year: From First Words to the

Fifty-Word Watershed to Grammar

Pointing opens the way toward language. Yet most parents find that true language emerges with the first words at around thirteen months. There is a fuzzy line between recognizable sounds and first words. By way of example, ''mama'' and ''papa'' will be among the early sounds interpreted as words by parents. With no intention of bursting bubbles, the sounds used to make these ''words'' are easy for babies to produce. Whether they really function as words is another story. To qualify as real, a word must sound like a known word and be used consistently—even in different contexts—to mean the same thing. So, for example, a child who uses the word ''flower'' to refer only to a flower on the front porch and not to the flower in the dining room vase is not credited with having spoken a word.

First words are often body parts or proper names (such as the name of the family pet), and they seem to be learned laboriously during the first few months. By sixteen months, most children say fifty words, most of which are names for objects and people in their environment (e.g., dog, daddy, ear, apple,juice, bottle). After children reach this critical mass of fifty words, something seems to happen inside that leads to a ''naming explosion.'' Typical eighteen- to twenty-month-olds can learn as many as nine new words a day. Children need to hear a word used only once to use it in a reasonably appropriate way.

This fifty-word watershed is also important for another reason. After children achieve this critical mass of words, they combine words for the first time. Thus, at about eighteen months, grammar bursts onto the productive scene. The first word combinations that children produce omit articles (e.g., ''the,'' ''an''), prepositions (e.g., ''to,'' ''from'') and inflections (e.g., plural ''s,'' ''-ing''), making the language sound ''telegraphic,'' or as if children were sending a telegram where words and particles cost money. These children can now say ''That kitty'' to mean ''That is a kitty'' or ''Daddy ball'' to mean ''Daddy has a ball.'' Everywhere in the world, children's first word combinations are expressing the same thoughts. Children ask for more of something (e.g., ''More milk''), reject things (e.g., ''No bottle''), notice things (e.g., ''Look kitty''), or comment on the fact that something disappeared (e.g., ''Allgone milk''). These children express entire paragraphs in their short utterances and talk about the ''here and now'' rather than about the past or future.

The Third Year: Refining Grammar

When children are two to three, their grammatical development becomes refined. Children may put together an actor and a verb, ''Mommy go,'' or a verb and an object, ''eat lunch.'' They are still limited by how much they can produce at a given time. If, for example, they wanted to say that they would not eat lunch, they could not utter ''No eat lunch'' in the early stages, but rather would have to limit their output to

''No eat'' or ''No lunch.'' Shortly, however, this window expands and the number of words they can use in a sentence increases.

During the middle of the third year, children become sophisticated grammar users who can speak in longer sentences and who begin to include the small grammatical elements that they omitted before. For the first time, they use ''ing'' on their verbs, saying ''running'' whereas before they could only say ''run.'' They begin to add tense to their verbs (e.g., ''walked'') and parents can even see evidence of grammatical ''rules.'' For example, the child who said ''went'' earlier may now know the past tense rule (add ''-ed'') and may now say ''goed''—much to parents' surprise. In such cases, however, ''went'' eventually reemerges and is used correctly.

The Fourth Year: Language Use in Social


Having mastered the sound system of language, learned the meanings of words, and learned how to structure sentences, children turn their attention to mastering the ways to use language in social situations at around three or four years of age. The child who says ''More milk'' is cajoled by parents to ''use the magic word—-please." Children now struggle to understand what people really mean to say. This is no mean feat, as is shown by the four-year-old who took the phone caller's sentence literally when asked, ''Is your mother home?'' This child answered ''yes'' and then hung up on the caller! Children need to learn that not all language can be taken literally.

Deeper Understandings of Language Development

As has been seen, children have a lot to learn in their first three or four years, and they constantly show what they know by what they say and how they say it. In fact, what they say has been the universal metric of language development. It is what the pediatrician records during routine office visits. And it is what a parent quickly jots down in the child's baby book. Yet, to pay attention only to what is on the surface would obscure most of what is going on in early language development. There is so much more going on behind the scenes.

In the late twentieth century and into the twenty-first century, the headline news in infant psychology has come from the ability to peer in on language development during the first year of life. Indeed, there has been a virtual explosion in understanding what children can understand even before they can speak. It has been learned, for example, that language learning starts in the womb. Newborns actually respond differently to a poem that was read to them constantly in the last months of pregnancy than to a new poem. They even show some recognition of their own mother's voice. Further, it is now known that even two-day-old infants can distinguish between their own language and a foreign language. Four-month-old infants recognize their own names. Six-month-olds understand the names ''mommy'' and ''daddy'' and can accurately indicate which label goes with which person. Research shows that eight-month-olds are sophisticated statisticians, finding patterns of syllables in the speech that they hear. They quickly learn that they had heard some patterns in the speech they heard and not others. And nine-month-olds already know that in English most words start with heavy stress as in ''KITCHen'' and ''STAple'' and not with weak stress as is found in such words as ''enJOY'' and ''reGARD.''

Advancements in science and new methodologies have also shown that ten-month-olds are no slouches. They comprehend about ten to twenty words, and by sixteen months they understand around one hundred words. By sixteen months these babies, who are one-word speakers, are five- or six-word listeners. They know that the sentence ''Big Bird is tickling Cookie Monster'' means something different than the sentence ''Cookie Monster is tickling Big Bird.'' Together these new findings indicate that babies who are only babbling and pointing are really working very hard—on the inside—to master the many components of language and to use them in an organized way. Before they utter their first word, babies have cracked the sound code, learned a lot about what words refer to, and have started noting the patterns of grammar. A complete account of language development will have to include what babies know, not just what they say.

Whether a person is French or American, lives in a castle or a tent, and is deaf or hearing, the course of language development appears to be the roughly the same. To be sure, there is some individual variation. For example, some children use mostly object names (e.g., ''book,'' ''dog''), while others collect and use more social language, such as ''please'' and ''thank you.'' The overwhelming impression gained from the study of language, however, is that despite the minor variations, children assemble their language orchestra in roughly the same way. This is even true for children who are lucky enough to grow up in a family in which more than one language is spoken. These children will learn both languages with ease. Young children are incredibly skilled at learning multiple languages at the same time.

Language Development When Things Go Awry: Everyday Problems

Though problems in language acquisition are relatively rare, there are a number of circumstances that can contribute to atypical patterns of development in which language might develop more slowly than is typical. Perhaps the biggest challenge is knowing when the problems are real enough to merit expert attention. The problems that have garnered the most attention are ear infections, speech/articulation problems, language delay, and stuttering.

Ear Infections

The most common cause for language problems are ear infections, more specifically, ''otitis media.'' Otitis media involves an accrual of fluid in the ear that results in temporary hearing loss. As one might expect, the condition has more severe consequences if it occurs in both ears than if it occurs in just one ear. About one-third of children suffer from extensive bouts of otitis media (greater than three bouts in the first year), and children who are in alternate care environments or who are around other children are reported to have higher incidents of the condition. On average, two-year-olds will have had six infections, each of which will have lasted for an average of four weeks.

Given the frequency of ear infections, it is no wonder that researchers have asked whether otitis media causes short-term or lasting effects on language development. The results of their studies, however, are mixed. Children with greater than three bouts of otitis media in the first year do tend to talk later than their peers. By the age of four years, however, these children have caught up in most areas. The research is somewhat mixed regarding long-term effects. Recent evidence suggests that there may be mild long-term effects of otitis media in two areas. First, children who have had many ear infections tend to have poorer attention spans in early elementary school. Second, they tend to be poorer at storytelling at seven years of age. While language does not seem to be affected then, there are some signs that children with early ear infections might have small but more lasting effects that could infringe on later school abilities.

Speech/Articulation Problems

Anecdotally, the cause for most concern comes from claims of immature or poorly articulated speech. While parents often worry about the four-year-old child who uses ''baby talk,'' saying ''Dat is not de way dat you sould do dis,'' most of these errors are well within the normal range of development. Children show remarkably consistent patterns as they attempt to pronounce common adult words. For example, a child might pronounce the word ''pot'' as

''bot. ''Notice that the ''p'' and the ''b'' are both sounds made with closed lips. Thus, they are easily confused. Or children might simplify the word ''bread'' into ''bed'' and ''spill'' into ''pill.'' Sometimes they also get the stresses and accents correct but fail to accurately reproduce the adult target. Words such as ''Sleeping Buddha'' for ''Sleeping Beauty ''and ''vampire'' for ''umpire'' in the opening examples of this article provide some sense of these errors of ''assimilation.''

Language Delay

As with speech/articulation problems, language delay represents another cause for concern for some parents. Many have heard the story of the child who says nothing until his third birthday and then, when sitting at dinner, asks for a fork in perfect English. When asked why he hadn't said anything before, the child said, ''Up to now, everything has been perfect!'' This joke is not far off the mark.

There are two forms of language delay. Some children understand everything but just do not talk. These children are not of real concern to parents. On the other hand, for some children, language development is not merely hidden from view but may not be progressing on course. Since the late 1990s there have been major developments in distinguishing between these two types of language delay. Parents seem to know the difference. They can often tell when children understand language and when they do not. If the child has not said even a few words by eighteen months or has not put two words together by twenty-four months, the parents should consider taking the child to a speech therapist. The child's hearing is the first thing that should be tested.


As with language delay and articulation, stuttering has both a common form and a more clinical form. Many parents find that at around age two, their children seem to stutter. They have a great deal to say and are not yet proficient at getting their message out. The result is a kind of verbal logjam. Children start a sentence, stop, flounder for a bit, and then start again. This is all quite normal and usually passes over the course of the next couple of months. By three years of age, speech therapists take stuttering more seriously. Stuttering runs in families and is more prevalent among boys than girls. Several cautionary notes are raised by speech therapists with regard to stuttering. First, if the child is stuttering at age two or two-and-a-half, it is important to not make a point of it. One should just slow down the rate of the conversation and proceed as if nothing has gone wrong. Bringing stuttering to the child's attention can often exacerbate the condition. Second, if the child of around age three is stuttering and the parent sees the child trying to inhibit the stuttering by making jerky motions with the hands or blinking the eyes while speaking, a speech therapist should be consulted.

Explaining Language Development

As noted earlier, language proceeds on a common course for most children. In fact, the weight of the scientific evidence supports the view that children are prewired to learn language. This strong view, however, leaves one pondering the role of input—the language that children are exposed to. Does parental input make no difference in the language development of the child? Can therapists make any difference in correcting language problems if things go awry? A brief review of the role of input in language will help set the record straight and will also provide some feel for the theoretical landscape that guides research in the field of language acquisition at the beginning of the twenty-first century.

First and foremost, it is known that language input must make some difference because all children do not speak the same language. French children will learn French, and Chinese children will learn Chinese. Thus, whatever is built in must be ''just enough'' to allow children to learn any language and not so much to determine the particular language a child will learn. That input makes some difference is therefore a given. What has been debated, however, is whether this input serves as a trigger for language development or as a mold. On the side of the trigger theories, researchers find that parents do not actively ''teach'' their children grammar. No parent would ever utter the sentence ''I goed to the potty.'' Yet most parents are overjoyed when they hear this from the child. They do not stop to suggest that the sentence should be ''You WENT to the potty.''

There is also mounting evidence for those who believe that parents mold language in children. Though parents do not teach children grammar, they do teach children when to say their ''pleases'' and ''thank yous.'' Further, it is widely accepted that parents who talk more with their children have children who learn more words and use grammar earlier. Input becomes apparent in the limited, but real, individual differences in language development between children.

Language development is the product of an interactive and dynamic system that has components of instinct and of input—of nature and of nurture. The human mind must be built so that young learners selectively attend to certain parts of the input and not to others. With respect to sounds, infants must recognize that the sounds of language are different than the many other sounds that come out of the mouth— sneezes, coughs, and burps do not name objects. In word learning, children must assume that words generally refer to categories of objects, actions, and events. This means that there is not a different name for every table or chair that one encounters in the environment. To learn a grammar, young minds must detect patterns of words but not pay attention, for example, to the syllable structure of every fifth word. Nature provides the starting points for language development, and nurture (the environment) drives the course of that development over time.

Given this interactive view of language, the job for the language scientist of the future is both to identify the selective tendencies of the mind and to see how, in concert with particular inputs, these built-in tendencies allow the child to construct a system that is capable of creating language performances over and over again throughout the course of a human life. The language orchestra, then, is a product of membership in the human species. Humans are given the instruments and the starting points. The language that a person hears around her everyday fine-tunes her sound and helps her build her repertoire. And each child becomes the conductor who pulls all of the components together in a flawless performance that is virtually completed by the time she is three years of age.


Golinkoff, Roberta Michnick, and Kathy Hirsh-Pasek. How Babies

Talk. New York: Dutton/Penguin, 2000.

Kathy Hirsh-Pasek Roberta Michnick Golinkoff

Baseball For Boys

Baseball For Boys

Since World War II, there has been a tremendous change in the makeup and direction of kid baseball, as it is called. Adults, showing an unprecedented interest in the activity, have initiated and developed programs in thousands of towns across the United States programs that providebr wholesome recreation for millions of youngsters and are often a source of pride and joy to the community in which they exist.

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