Prenatal language learning

The fetus is constantly exposed to his mother's speech, and also to the speech of other persons conversing with her. From about six months of prenatal age, he gets used to the sound pattern of this variety, above all to its prosody and, beyond the language system proper, to the speech melody and its emotional variation. These are not the central parts of the language system that he will have to learn after birth. However, they become deeply wired in his brain. Even a few days after birth, an infant can distinguish his mother's language from other languages. He will learn this language with the characteristic native speaker's “accent”. At the same time, this prevents most people from acquiring an additional language with its prosody and the pronunciation habits and speech melody which characterize the speech community. Even if someone speaks a second language flawlessly, these phonetic features mostly persist from his native language.

Stages of first-language acquisition

Every healthy child can learn any language if brought up under human conditions. The restriction refers to those children who were denied communication with caretakers and who did not, in fact, learn to speak. Primary language acquisition is bound up with social interaction. This is partly different for second language acquisition. Some adults are able to learn a language autodidactically.

Both Wernicke's and Broca's area are shaped in early maturation. On the basis of the innate semiotic faculty, infants learn to communicate before they understand and utter their first words. By the age of five months, they scream to communicate disagreement with their situation. With about half a year of age, infants start babbling. This is not an attempt to imitate the speech that they hear, but instead a spontaneous attempt to communicate.

Language learning proceeds in synchrony with the acquisition of motor skills. Progress in language correlates significantly with the ability to sit and to walk independently. Before infants start speaking, they use gestures. This starts at the age of nine months. Gestures are acquired easily, will subsequently be accompanied by speech and may or may not be ultimately replaced by speech.

Communication presupposes an intention on the part of the sender. The child learns to employ a semiotic system because he understands that it serves to transmit one's intentions and to create shared intentions. In the beginning, language is, in the first place, a form of interaction. Before individual linguistic units such as words and syllables are learnt, illocutionary acts are performed. First are directive acts, indicating that the child wants the interlocutor to do something. Only then follow declarative acts. The first declarative utterances transport existential and presentative propositions, meaning things like ‘(look) there is an X’. Third come interrogative acts, typically meaning ‘what is that?’ In their original form, such acts do not require vocal signs; they may be executed by gestures, typically by pointing to an object or a place (Tomasello 2009: 72).

At about one year of age, the child starts speaking. The basic communication unit is the utterance. An utterance by a parent is understood holistically; i.e., in the beginning the child understands what the speaker intends without analyzing the utterance. The child's own utterances consist of one word, which is why this stage is called holophrastic. The word uttered generally corresponds to what would be the focal component in a complete sentence. The prosody on the word hints at the communicative intention.

Only to the extent that this works increasingly well does the child start analyzing utterances. At about three years of age, the child can segment utterances into words. At this stage, he identifies words as units recurring with a similar function in the utterances understood. This is when acquisition of vocabulary actually involves words, not utterances.

The pointing gesture may be accompanied by utterance of a word, e.g. car. This may be communicatively equivalent to an utterance like .

The subsequent two-word utterances consist of two words connected by some syntagmatic semantic relation between their designata, such as an object related to a place or a quantifier¹ specifying a mass or a set. The prosody guarantees the unity of the utterance. There is not yet any grammar; the words do not yet belong to grammatical categories, and the relation between them is not a syntactic one.

With about two years of age, the child can handle actively and passively utterances consisting of two or more words in the order required by the grammar. However, he is not applying a rule of syntax; he has learned a set of sequences each of which is based on a particular item, like a phraseologism.²

At three years of age at the earliest does the child abstract constructions formed by rules of grammar and apply them to further words belonging to the categories in question. He does this by applying schematization and analogy.

More complex syntactic constructions like complex clauses and interrogative clauses are formed on an item-basis even yet at an age of four years. Only then are general rules for forming such constructions abstracted from a set of such formulas.

In this phase, as children are discovering rules, they often overgeneralize them. Only later certain factors constrain the production; among these are entrenchment of grammatical constructions, preemption of ungrammatical constructions by obvious avoidance on the part of adult speakers and the formation of semantic subclasses on the basis of pivot words.

Further expansion of language competence involves use of other media, specifically writing, and perfection of the cognitive operations and motor skills required for fluent and accurate speaking. It also involves complementing procedural competence by reflective competence.

The role of the innate semiotic faculty

Advocates of formal theories of grammar (Chomsky 1995) have made the following set of claims:

• The child forms a grammatical competence of such a complex system as the language of his environment.
• He must abstract this system from the input that he perceives.
• For this operation he only has very simple and general principles of behavioristic learning theory at his disposal.
• The input that he is exposed to is far from sufficient to lead to the actual result; i.e. the input does not contain all the complex constructions which are nevertheless mastered, and moreover many utterances heard are simply ungrammatical or otherwise deficient.
• And yet the child succeeds in building a complete competence of the language system in an amazingly short time, viz. essentially in the five years following his first utterance.

This argument has been known as the poverty of the stimulus. Its proponents have concluded that general processes of a learning theory would not suffice to construct the competence of the language system that the child does, in fact, acquire; so the only possible explanation of the facts is an innate rather specific language faculty which goes by names such as the language acquisition device or universal grammar (Lust 2011, Pietroski & Crain 2012).

However, some crucial claims presupposed by the argument do not stand an empirical test. As a matter of fact, especially in early childhood, most parents carefully teach their child to speak, correct him and provide him with models of all the constructions that the child will afterwards master. And to the extent that parents fail on this task, the child does learn the language imperfectly and with corresponding delay. On the other hand, the child is not faced with pure formal structure and therefore does not apply purely formal principles to analyze it. Instead, he is faced with meaningful constructions consisting of meaningful and functional elements. From the overall holistic meaning of an utterance that he starts from, he can individuate subfunctions and assign them to components of the utterance and to its structural properties.

¹ A quantifier is a word indicating the size of a set or a mass, like all, some, more.

² A phraseologism is a lexicalized complex expression, like be fed up with something or out of date.