Children fullfill a huge task when they successfully learn their mother tongue. Other than adults who attempt to learn a new language they do not have to study vocabulary or grammar explicitly, but they seem to absorb all the words and rules which are presented to them. This essay will shed some light on language development in children, so it deals with infantine speech perception and production, the main stages of this process and the mental lexicon. I attempt to show that children's mental lexicon and adult's mental lexicon are essentially the same.
Main Stages of Speech development
Children start to learn their mother tongue from very early on by listening very closely. In fact, they don't even wait until they are born. They tend to prefer their native language over others and their mothers voice over other women's voices. (cf. O'Grady, 2005: 143) Infants are presented with quite a complicated task, since they have to learn how to understand and produce sounds, words, meanings and sentences without explicitly learning any rules and they do remarkably good at that. According to William O'Grady, children can “make out the intonational contour and other features of the speaker's voice” (2005: 143) By tracking the head movement after teaching them to choose the auditory stimulation they prefer, one is able to make definite claims about their preferences. In this particular experiment showed that unborn children can differentiate between a familiar bed time story, one which has been read to them before they were born, and one they have never heard before by means of the the story's rhymes. (cf. O'Grady, 2005: 144)
After the child spent enough time listening, usually around the age of four to six months according to O'Grady, they start to produce squeals, yells, growls, trills with the lips and marginal babbling until it evolves into real babbling around the seventh to twelfth month. Finally, between the age of ten to eighteen month the child produces his first word and enters a world of meaning and syntax without knowing what great journey lies ahead. (cf. 2005: 143) Especially syntax is one of the components of speech that is hard to master, but even at that point in time the child is well prepared due to all the conversations he witnessed during his first year after birth. When learning the meaning of words, especially function words, children tend to stick to a certain learning order. ”The plural -s and the progressive -ing on verbs are […] the first to appear, followed by the prepositions in and on, the articles a and the, and only much later by the forms of be such as is, was, were [and] are.” ( Bruner et al., 1979: 55)
Surprisingly, in most cases children are able to distinguish between single morphemes just by listening, although people do not make pauses between words when speaking. This may account for the fact that the learning child sometimes gets a morpheme wrong, when it often occurs in combination with another one, like it's. Although it is two morphemes the child may consider it to be one. Subsequently, the child uses the combination of morphemes where it is advisable and in some places where it is not (cf. Bruner et al.2005:50)
“When word combinations first appear, children are sensitive to the adult conventions of ordering words in sentences, and in English these are the first rules of grammar they learn.” (Bruner et al., 1979: 48) This ability, namely to absorb the rules for the use of language from the spoken word enables him to make maximum use of the little vocabulary he knows. From very early on the child is more likely to select the word order used by adults to declare a relationship. According to Bruners et al. during the first stages of language production children are “obsessed with the relationship of possession […], the relationship of location [...], labelling […] and nonexistence:” as in “My teddy”, “Car garage”, “This steamroller” and “No more soup.” (1979: 49) During this period child concentrate on actions, relationships and their immediate surroundings. Relations involving experience do not appear as often. At this time they understand that some things are caused by others and can remember which person initiated an action. (cf. Bruner et al., 1979: 50) These early combinations of words show that children are able to make connections between occurrences in their immediate surroundings. Moreover, this indicates their understanding of the world and their speech production to increase comparable. “The child unquestionable perceives the world through a mental fog. But as the sun of experience rises higher and higher these boundaries are beaten back”. (Chambers qtd. in Bar-Adon and Leopold, 1971: 99) The mental fog that is described in the quotation illustrates the way children have to deal with language quite good even if I do not agree with the “mental fog” approach to language learning.
The child is not only exposed to grammar but also to many words which need to be understood and assigned to objects or acts. Children are great listeners and extremely comprehensive. They are very much aware of the subtle meanings of small morphemes and articles. Moreover, they infer rules for the use of the words from the morphemes and the use of articles as found in a study by N. Katz et al. Depending on the use of articles the children either accepted the nonsense word as the name for a specific doll, if the article was omitted or as a name for a certain kind of doll if there was an indefinite article used. (cf. 1974: 472)
In the beginning children cannot grasp every nuance of a meaning of a word, which leads to over- and underextension. Applying the word dog for everything that has four legs is a common example of overextension. The word dog is overextended to everything which happens to have four legs which at that point is everything the child takes into account, when deciding what 'dogness' means. So horses, cats or pigs may all be referred to as dog at that time. Since he does not know the full adult meaning of the word or words for the other animals, he uses his small vocabulary to refer to as many things in the world as possible. The child will proceed to see and add features to the word dog in his mental lexicon over time, until his understanding and the adult concept correspond. (cf. Atchison, 2012: 214)
The “mental fog” viewpoint and the “prototype theory” attempt to analyse children's language learning abilities. But while the “prototype theory” can account for overextension and false labelling of things, the “mental fog” viewpoint cannot. According to the prototype theory as presented by Atchison, children, like adults, look for clusters in things. They refer to a certain thing not by accident, but because it bears a resemblance to a thing they have successfully labelled with that word. These chain-complexes may occur strange to an adult, but they make sense to a child and his restricted vocabulary. Children, as already mentioned, will make as much use of their small amount of words as possible, but “they are over-influenced by appearance.” (Atchison, 2012: 217) As yet they do not focus on the same features as adults. When a child learns a word like moon it breaks the borders of adult understanding of that word by referring to everything circular as “moon” or something shiny. (cf. Atchison, 2012: 216) Only over time, will the child learn what sufficient characteristics are needed to be classified as moon.
Some of the examples presented above show in what way infant speech differs from adult speech and I will go on to examine this topic in the next section.
Differences to Adult speech, Production and Perception
Languages are always changing and so is speech production. Speech adapts to meet the requirements of its users. Let alone in order to engage in a meaningful conversation language needs to account for time, places, different people, various objects and acts. This becomes very clear when we take on the numerous words which have changed in meaning and usage to describe modern phenomenons. Selfie, unfriend, GIF or omnishambles are only a few of the many words that are used to refer to certain meanings which, if it was not for these words would be things or meanings without a label. For one thing an infant learning his first language is of course not at all concerned with these neologisms, at least not in the very beginning. Even so these words serve as an example for the labelling process infants pass through. During their first years every meaning is unbeknown. Moreover, every single thing in the world is new to them and in order to communicate about any of these overwhelming denouement they need to label things and memorise words which fortunately already exist so they do not have to make up new ones. However, “the child must infer its meaning from the uses he hears others make of the word and from their reactions to his usage.” (Demopolus and Marras, 1986: 154) Subsequently the child's speech has to differ significantly from that of adults since he does not only have to learn the words but also the very meanings of things. Overextension and underextension for instance derive from the fact that meaning and the corresponding word are not always learned simultaneously, but the child still wants to talk. As a result of the child's special focus on appearance he makes a number of seemingly strange classification. (cf. Atchison, 2012: 216) In that respect he may also apply rules to words which are not formed according to the rule the child assumed. For instance, a child who adds -ly to an adjective in order to form an adverb applies the correct rule. If, however the -ly is applied to good, fast or hard, the child ends up with a word which does not exist or one which carries a different meaning. (cf. O'grady, 2005: 195) Usually children notice their mistakes over time. By being exposed to the legitimate version of the word, they realise that adult speakers do not use the word they created and instead accept the adult version. According to O'Grady this is due to the principle of contrast which is used by the child. (2005: 195) The principle of contrast, as presented by O'Grady says that two words should never have the identical meaning. According to these children stop to make use of their own inferred version of a word (like goodly) and replace it with the word adults use because if they did not, they had created another word with the exact same meaning. But the most striking differences between infant and adult speech are the lack of fluency, limited number of words, irregular grammar, category errors, mistakes in morpheme choice, pronunciation errors and a wider gap between active and passive vocabulary.