Look at Graph 1. It shows the sucking rate of four month olds to ‘pa’ or ‘ba’. As you can see the babies soon become inhabituated, and the sucking rate drops. When ‘pa’ is introduced the baby becomes more stimulated and the sucking increases.
Graph 1 (Gleitman, 2003)
Babies respond to just about all sound distinctions made in any language. Even Japanese babies can detect the difference between ‘pa’ and ‘ba’, as easily as an English baby, despite the fact that these phonemes are not used in Japanese. This soon diminishes around 12months old as the average child starts talking so that it listens specifically for the language that it will speak.
At around 12 months old, this is the average beginning of a child to start speaking. (W, Stern, 1924). Yet there are variations. There are children at the age of 9 months that can use one or several words, and then there could be an 18 month that still uses nothing. Psychologists say there is no need to worry, due to the fact that some children might just be very expressive in their actions and gestures. One word state (12 – 18 months) has lack of function words and suffixes. This may be due to the fact that although they do hear these items, the parent just does not emphasise them in the same way as she would when using verbs or nouns. That is why children of this age usually utter verbs, nouns and modifiers.
The pace of vocabulary learning soon picks up to about 10 words a day. (Approximately 18 -24 months). This is early sentence stage. The majority of sentences are incomplete. It seems that children are excellent at taking in new words, organising them and storing the information. However phonemes and syllables seem to challenge children. For instance a toddle reaches to the mother crying out ‘ca-ree-oo’. They assume that there is a three syllable word for ‘pick me up’. The problem has been identified that phonemes and syllables run right into each other and overlap in speech. Before a child of early language development knows the meaning of words they have been said to be ‘sensitive to these frequencies, busily recording cases of frequent syllable sequences and using this information to decide which sequences are an actual words of language.’ (Gleitman, 2003) this process has been demonstrated experimentally, for example ‘bidaku’ experiment. (Gleitman, 2003 Page 341).
Children begin to understand a few word meanings during the first year. In children of this age interactions seem to be either with adults such as a ‘hi’, or by the use of names such as ‘dada’ and the rest are simple nouns such as duck. however pronunciation is not always clear. Children of this age also miss out function words and suffixes such as ‘the, and, and –ed’. Although these items are most likely heard the most by infants, they rarely use them. Children discover the meanings of words by hearing a word, then look around to see which object is in view when the sound is heard. It seems children are impressively accurate in their understanding of word meanings. (P.Bloom, 2000), and the errors that do occur soon correct themselves. By the time the child has one-hundred-word vocabulary, he is almost always correct when using words to refer to things and events.
These first examples of language use often involve direct labelling of objects in current view without the ability to talk about things that are not in sight. Around 18 months old the ability to do this will come into place. (Perceptual & Conceptual properties of Child Language.)
Studies have shown that before a child of a young age can produce sentences he can infact understand in a basic way, both syntax and semantics. One experiment documenting this fact involved children of aged children about seventeen months. The children sat on their mothers lap, watching a two video screens. On the screen to the left, Big Bird is tickling the Cookie Monster, and on the right the Cookie Monster is tickling Big Bird. Half the children heard a voice saying, ‘Oh look! Big Bird is tickling Cookie Monster.’ The other heard the reverse sentence. Hidden observers recorded which screen the children turned to. The finding was that the toddlers looked first at the screen that matched the sentence they heard. This is amazing since these children were only in one word utterances stage of development. (Hirsh-Pasek, Golinkoff, Fletcher, DeGaspe-Beaubien, & Cauley, 1985).
The progression of language happens rapidly. Between age 2-3 sentences start to become longer. Function words start to appear. There are developments of semantics, by using two morphemes together as in ‘more milk’. The child is using a syntactic rule about how morphemes are combined to convey meaning. The use of spatial concepts such as ‘in’, ‘on’ are being used. Also there is the use of pronouns such as ‘you,’ ‘me,’ ‘her’. Children of a younger age have problems in acquiring syntax and semantics However as the child goes through the years of 3-5 syntactic rules become increasingly complex. From combining two morphemes, the child goes on to combine words with suffixes or inflections (-s or -ing, as in papers and eating) and eventually creates questions, statements, commands, etc. The child also learns to combine two ideas into one complex sentence, as in "I'll share my crackers if you share your juice."
By five years the average child sounds like an adult in the forms of his/her speech. It has been shown that children learn the grammar of their language by extracting rules that they use experimentally when speaking. Children often start off using past tense correctly at around the age of 3; they apply it to regular verbs but not to irregular ones. Such as ‘walked’ and ‘talked’ and also correctly use irregular forms such as ran, came and ate. However by the age of four or five, children start to say irregular verbs as though they were regular. Hence ‘runned’ and ‘holded’. These errors in language help suggest that imitation is not solely how language is learned. Investigators have found that once children have identified the pattern of simply adding the –ed suffix to a verb when speaking of past, a child gets carried away, and so over regularization errors occur. This soon decreases when a child realises that there are certain exceptions to the pattern. (Gleitman, 2003).
In conclusion it has been identified that as the child naturally reaches language developmental milestones, simple skills need to be mastered before the more complex skills can be learned. There is a general age and time when a child reaches these milestones. By eighteen months of age, most children can say eight to ten words. By age two, most are putting words together in crude sentences such as "more milk." During this period, children rapidly learn that words symbolize or represent objects, actions, and thoughts. At ages three, four, and five, a child's vocabulary rapidly increases, and he or she begins to master syntax (sentence formation) and semantics (word and sentence meaning).
References
Gleitman, H, Fridlind, A.J., & Reisberg, D. (2003) Psychology (6th Edition). W.W Norton & Company Ltd.
Hurlock, E (1950) Child Development. New York. McGraw-Hill Book Company, Inc.
Nelson, K (1985) Making Sense, The acquisition of Shared Meaning. New York. Harcourt Brace Jovanovich, Publishers.
Stern, W (1924) Psychology of Early Childhood up to the sixth year of age. London. George Allen & Unwin Ltd.
Speech and Language: Developmental Milestones (April 2001) National Institute on Deafness and Other Communication Disorders. Retrieved Sunday, 04 December 2005, from the World Wide Web; http://www.nidcd.nih.gov/health/voice/speechandlanguage.asp#mychild