Babies begin to make quieter, lower pitched and musical sounds called cooing. This creates a wider range of vowel and consonant sounds such as; -us, ks and gs.
Between 2 - 5 months babies start to string these sounds together to create a sequence like: khu and guu.
Babies also vary pitch and loudness but are missing intonation and rhythm.
Babies stop for breath at random intervals so it lacks the natural rise and fall of adult speech.

Babies start babbling stringing together long sequences of repeated sounds such as bababababababa or dadadadadadadadada.

From 9 months more varied babbling occurs (vegetative babbling).

Consonants and vowels change from one syllable to the next ada, maba.

S and sh sounds appear but the babble remains jerky and erratic. Some will be loud, some soft and speed is very varied.

A significant change develops suprasegamental features (prosodic features) of melody and rhythm that makes speech natural and fluent are occasionally hear.

Parents think their baby has spoken its first word but it is actually just practising sounds.

Crystal says "the child has gotten their act together but has yet to learn what that act is for

Tone and rhythm are signs that language will soon be heard. This is when the nationality of a baby will affect language acquisition.

At 13 months short utterances of one or two syllables are heard.
Proto-words are used but aren't real words because language must have meaning.

The first real words appear which combine sound and meaning. One word utterances are normal such as teddy, gone, more.
Some two or three words are joined together in the child's mind as one wordallgone, ready-steady-go.

Approximately 60% of single word utterances are nouns and approximately 25% are verbs.
If prepositions like in are heard, the child is using them as a verb.
Suprasegmental features help create meaning.

At 18 months two word utterances are head: coat off, kiss teddy but the utterances are abrupt and telegrammatic.
The child is learning how to make sentences with all the necessary features, eg. prepositions (in there), possessive pronouns (my dolly) and personal pronouns (he cold, me want).
Children have trouble with personal pronouns (this is hims car).

Environment plays an important part in the words children acquire and speak. Children growing up in the countryside will perhaps use words differently to children growing up in the city.
But there is a general pattern that many early words are nouns and that is true for all children of all backgrounds.

Argued there is a noun bias in a childrens vocabulary which reflects the relative frequency of nouns in the English language (nouns outnumber verbs 5:1 in most dictionaries).

She found that 60% of childrens first 50 words are nouns.

'The child has got their act together but has yet to learn what that act is for'

A survey by Crystal found linking words begin in year 7 (age 6 - 7/8) and increase in number at 8 years old but 12 year olds use far fewer linking words than adults and the words they used were still simple: now, then, so, anyway, though and really.

The most common form of overextension when a word meaning is stretched to mean everything with similar properties to the actual word.
For example calling rats, rabbits and squirrels, 'mouse'.

This is found in 15% of Rescorla's cases and this is when the meaning encompasses everything with a similar function.
For example a child calling a scarf 'cat' when they stroke it.

This is found in 25% of Rescorla's cases which convey some sort of abstract information.
For example, a child calling an empty cot 'dolly'. This could be a mislabelling of the object but could also be because the dolly is normally in the cot but isn't on this occasion.

Piaget watched his daughter Jacqueline and found that she called her dog bow wow (her word for dog) but also the rug and porters. Over time, she stopped calling the rug and porters bow wow, however, she would only label her dog as bow wow and not all dogs, underextending the meaning. She finally began to call every dog bow wow, learning the right extension of the words meaning.

At 18 months a childs productive vocabulary (words they can use) is around 50 words they can say.
At 2 years the productive vocabulary is at 200 words.
At 3 years the productive vocabulary is at 2000 words.

Linguists estimate that the figure of words that children learn are 10 words a day.

A specific object -> whisk, sieve, grater, colander.

The category -> kitchen utensils.

When a child broadens the meaning of words to encompass many things with similar properties, eg, labelling rats, squirrels and rabbits all as 'mouse' or every round fruit as 'apple'.

When a child narrows the meaning of a word, eg. a child may have an idea what a banana is and can use the word when faced with a banana on a plate but can't when faced with a picture in a book or a bunch of bananas.

Beginning of a word, normally one or two syllables, but isn't a word because language must have meaning.

Associating sounds with objects in the world around the child, linking words to things.
Understanding the concept of labels.

Starting to explore the extent of a label - often the stage where overextensions and underextensions happen most frequently.

Making connections between the labels that they have developed.
Understanding similarities and differences as well as relationships and contrasts.

He conducted the experiment on children between 3 - 12 years (developmental years).
He did these experiments at ages 3, 6, 9 and 12.
He gave the children cups and glasses and got them to label them.

At 3 years old, the children called them all 'cup' and the only distinction they could make were the size 'big cup' and 'little cup'.

At 6 years old, the children labelled them based on what it was made of so they could make a distinction between a cup and a glass and also used plastic cup.

At 9 years old, there wasn't much difference between 6 and 9 year olds, however, 9 year olds could combine the material of the cup along with the size.

At 12 years old, the children labelled the cups by its function and appearance.

He said that all behaviour is the result of the conditioning we have experienced rather than freedom of choice.
He proposed that children learn through positive and negative reinforcement.
He also suggested that children learn through imitation and operant conditioning (positive and negative responses given by caregivers).

If a child is using a grammatically accurate sentence, a mother might praise the child for their efforts. Because of this positive reinforcement, the child is more likely to speak in that way again. The same can happen in a negative way, however, this could cause the child to stop speaking altogether.

A problem with this argument is that children are more likely to be corrected on the truth value of their statement than on the grammatical accuracy.
If a child said 'we runned away from nursery' the parent is more likely to question if that was the truth or not, than corrected the verb to 'ran'.

Another problem with this argument is that there is evidence to suggest that children do not respond to correction and that could hamper their language development.

One of the main arguments against the imitation theory is that children do not suddenly produce grammatically complete standard English sentences, which could be expected if the child was imitating those around them.
Instead, they build up their language, gradually refining their speech as they develop.

He created a response to Skinner's behaviourist theory which took an opposing view.
Chomsky introduced the concept of a Language Acquisition Device (LAD) which went against the view of the human brain being like a blank canvas (Aristotle).

Chomsky argued that the human brain has a naturally programmed ability to learn a language and an ability to work out the systems in terms of grammar and syntax.

Universal grammar is used in relation to Chomsky's theory to describe this global capacity for children to learn languages at similar rates and in similar ways.
The similarities between world languages and their grammatical structure have also been used as evidence for this innate system.

The idea of virtuous errors are often used as justification for LAD as a child makes errors in their grammar because they are attempting to apply rules they recognise from the language around them.
For example, a child saying 'I swimmed' is logically using the past tense rule by adding -ed onto the end of swim to turn it into the past.
However, it is unlikely for a child to have heard this construction from a caregiver, so therefore it can't be imitated.

However, a reason why LAD has been rejected as a theory is because it does not place enough importance on the role of caregivers and how they influence language acquisition, as children who lack exposure to language and interaction will never really catch up with their language acquisition.

This challenges the nativism theory because between the age of 20 months to 13 years, she was locked up by her father and exposed to no social interaction or speech. When she was found in 1970, she was found to have no speech.
Even though there were interventions, she could only acquire language to a very basic level.

This reinforces the concept of a critical period as Genie was not exposed to language at a young age and by the time she was offered the support she couldn't learn language to the same fluency.

He coined the term critical period which is a learning period up to 7-11 years and is believed that in the first few years of life, sufficient social interaction and language is essential in order for the child to gain full mastery of language.
Early childhood is the best time for a child to acquire language.

He rejected Chomsky's LAD theory and focused on the importance of a child's interaction with caregivers as the key to language development. He suggested the importance of a Language Acquisition Support System (LASS). Bruner places emphasis back on social situations and how children can acquire language in countless opportunities with the help of significant adults who provide meaningful imput.

He suggested that carers question, encourage and support the child through scaffolding which allows the child to gradually develop their speech.

Bruner also focuses on the need for quality input from carers to facilitate learning.
For example; if a child saw a picture of a zebra and called it 'horse' then the caregiver would offer support by explaining the differences between the animals so the child is able to differentiate the animals themselves.

He suggested the importance of 'doing' (kinesthetic learning) for a child to develop and the importance of a caregiver to act as a more knowledgeable other.
The more knowledgeable other is in a position of having more knowledge and understanding and can push the child to the next stage (next zone of proximal development). This is the area just beyond what the child is already able to do, so the caregiver might offer the necessary support which is scaffolding so that the child can venture beyond their current ability with language or academically.

He also rejected Chomsky's idea of universal grammar and argues against language being driven by a special instinct. Instead the ability to learn a language is primarily social and relies on using the same cognitive process as other forms of learning, for example, walking or drawing.

Tomasello identified between the ages of 9-12 months, children make use of a pattern forming ability which allows them understand the intentional aspect of language.

Rather than the result of a built in grammar system, that supports the learning of a language, usage-based linguistics advocates for the child actively building and using templates for grammatical structures based on sensory inputs or interactions with caregivers.

She carried out a test to see children's use of the -s plural.
She gave the children a picture of an imaginary creature called a 'wug' and asked the children to finish the sentence 'here's a wug, now here's another wug, there are two ...' and children tended to create the plural wugs.

Of 4-5 year olds, 76% formed the regular -s plural whilst in 5-7 year olds 97% of children did the same.

This test was done with multiple other made up words and performed by other people which all yielded similar results.

Young children begin by learning patterns and have slots which can be filled with different items such as 'where is the toy/dog/book'.

Once a child has heard variations like that in their language they are able to build up more abstract constructions by analogising across examples.

The idea that these reliable patterns (called slots and frames) give the child a foothold into learning more complex syntax.

Construction based models focus on real language used between children and parents and see rich language used in the child's environment.

Instead of picking up single words and combining them into a pre-programmed set of abstract grammatical rules, this models suggests that children pick up chunks of language and create their own productive structures from them and adapt them to create new and creative forms of their own.