Language acquisition refers to how humans can develop the ability to understand and use

language. Numerous language acquisition theories in the English Language aim to

understand and explain how the process begins and progresses. There are 4 main the most
popular theories of language acquisition in the English Language and these are:

 Behavioural Theory
 Cognitive Theory
 Nativist (Innateness) Theory
 Social Interactionist Theory

There are also certain theorists of language development who have contributed to the study
of a particular language acquisition theory.

Theorists of Language Development Language Acquisition Theory

Burrhus Frederic Skinner Behavioural Theory

Jean Piaget Cognitive Theory

Noam Chomsky Nativist (Innateness) Theory

Lev Vygotsky, Jerome Bruner Social Interactionist Theory

Behavioural theory

The Behavioural theory of language acquisition, sometimes also called the Imitation
Theory, is part of behaviourist theory. Behaviourism proposes that we are a product of our
own environment. Therefore, children have no internal mechanism or ability to develop
language by themselves. Behaviorists, like B.F. Skinner, argued that language acquisition and
development are learned behaviours. The psychologist, in his book from 1954, titled Verbal
Behavior, claimed that we learn the language first by observing our caregivers (usually
parents) and imitating their sounds (modelling or imitation component in Skinner’s theory),
by classical conditioning, that is, associating events: over repeated exposures, infants may
learn to associate a given object with a sound or word for that object, and then by modifying
our use of language through rewards and punishments, a process known as operant
conditioning.

operant conditioning
Operant conditioning is a way of learning that focuses on the reward (positive
reinforcement) or punishment (negative reinforcement) of desired or undesired behaviour.
Skinner suggested that children first learn words and phrases from their caregivers or others
around them and eventually try to say and use those words correctly. In this case, operant
conditioning occurs when a caregiver responds to the child's attempt at using language. If
the child uses language correctly, the caregiver may respond by showing their approval. If
the child makes a request, such as asking for food, the caregiver may reward the child by
providing it. This is an example of positive reinforcement. If the child, on the other hand,
uses language incorrectly, makes a mistake, or is incoherent, they are more likely to receive
negative reinforcement from the caregiver. They can be told they're wrong and then be
corrected or simply be ignored. Negative reinforcement teaches the child which mistakes to
avoid and how to correct them.

Cognitive theory

The Cognitive theory of language acquisition suggests that the primary drives behind our
actions are our thoughts and internal processes. A Swiss psychologist, Jean Piaget, assumes
that children are born with relatively little cognitive ability, but their minds develop and build
new schemas (ideas and understanding of how the world works) as they age and experience
the world around them. Eventually, they can apply language to their schemas through
assimilation (fitting new information into what is already known) and accommodation
(changing one's schemas to support new information).
Piaget believed that cognitive development had to come before language development
because it would be impossible for children to express things that they do not yet
understand. A child has to understand a concept before he or she can acquire the particular
language which expresses that concept. For example, a younger child with no sense of time
couldn't express things in the future tense or speak hypothetically, no matter how much
they are taught language.

Piaget proposed that this cognitive development could be split into four
stages: sensorimotor, preoperational, concrete operational, and formal operational, each
involving a different aspect of language acquisition.

Piaget's four stages of cognitive development

First is the Sensory-Motor Period. This takes place from birth to around two years of age.
  at this stage, children are developing "action schemas" or sensory coordination such
as sucking or grasping to assimilate the information about the world, and interacting
with their environment by feeling and playing with things.
 their use of language extends primarily to babbles and few spoken words.
 during the sensory-motor phase, children's language is "egocentric," meaning they
talk either for themselves or for the pleasure of associating anyone who happens to
be there with the activity of the moment.

The next stage, called Pre-Operational Period, takes place from ages two to seven.

 at this stage, children are developing "mental schemas," which enable them to
"accommodate" new words and situations.
 children's language becomes "symbolic" allowing them to talk beyond the "here and
now," to talk about things such as the past, future and feelings,
 to use language with a better grasp of grammatical structure, context, and syntax.

Next is the Concrete Operational Period. It takes place from ages seven to eleven.

 at this stage, children understand concepts such as time, numbers, and object
properties
 gain reasoning and logic, which allows them to rationalise their beliefs and speak in
greater detail about their own thoughts and the world around them.
 they can also understand how outcomes or viewpoints may differ.
 the stage involves "animism" which refers to young children's tendency to consider
everything, including inanimate objects, as being alive.
 language is still considered egocentric because children see things purely from their
own perspective.

Finally, we have the Formal Operational Period. This takes place from twelve years old to
adulthood.

 at this stage, children can engage in higher reasoning and think and speak about the
abstract, such as hypotheticals, morals, and political systems.
 language is essentially unlimited, as there is no cognitive limit to one's understanding
of the world at this stage.
 children’s language at this stage reveals the transition of their thinking from
immature to mature and from illogical to logical.
 they are also able to "de-center" or view things from a perspective other than their
own.
 it is at this point that children's language becomes "socialised" and includes things
such as questions, answers, commands and criticisms.
Nativist (Innateness) theory

The main hypothesis of nativist theory is that children have an inborn or innate faculty for
language acquisition that is biologically determined. The human species has evolved a brain
whose neural circuits contain linguistic information at birth and this natural predisposition to
learn language is triggered by hearing speech. Noam Chomsky proposed that this biological
predisposition to acquire language regardless of setting is due to an instinct or drive for
language learning which he called the language acquisition device (LAD), which is used as a
mechanism for working out the rules of language. He argued that even if a child is not
educated in their country's language, as long as they grow in a normal environment, they
will still devise a system of verbal communication. Therefore, there must be an innate,
biological component to language acquisition. Chomsky suggested that the language
acquisition device (LAD) must be located somewhere in the brain, serving as an encoder that
provides us with a baseline understanding of grammatical structure. As children learn new
words, they are able to incorporate them into their use of language independently.
Chomsky argued that this independent 'building' of language is evidence that language
acquisition is biological and not purely a product of being taught or copying caregivers.
According to Chomsky, the LAD contains knowledge of universal grammar – the basic shared
grammar rules that all human languages share, thanks to which infants acquire grammar
because it is a universal property of language, an inborn development. Children under the
age of three usually don't speak in full sentences and instead say things like "want cookie"
but yet one would still not hear them say things like "want my" or "I cookie" because
statements like this would break the syntactic structure of the phrase, a component of
universal grammar. Another argument of the nativist or innate theory is that there is a
critical period for language acquisition, which is a time frame during which environmental
exposure is needed to stimulate an innate trait. The critical or sensitive period
hypothesis claims that there is an ideal period of brain development to acquire language in a
linguistically rich environment, after which further language acquisition becomes much more
difficult and effortful. The hypothesis was first proposed by Canadian neurologist Wilder
Penfield and co-author Lamar Roberts in their 1959 book Speech and Brain Mechanisms, and
was popularised by Eric Lenneberg in 1967 with Biological Foundations of Language. There is
much debate over the timing of the critical period with respect to SLA (second language
acquisition), with estimates ranging between 2 and 13 years of age.

Social Interactionist theory

Associated with Lev Vygotsky and Jerome Bruner theory of social interaction incorporates
nurture arguments in that children can be influenced by their environment as well as the
language input children receive from their caregivers. The social interactionist theory
proposes that language exists for the purpose of communication and can only be learned in
the context of interaction with adults and older children. Children are born with an ability to
develop language but they require regular interaction with their caregivers or teachers to
learn and understand it to a level of full fluency.

A caregiver may also use child-directed speech (CDS), altering their own use of language to
make it easier for a child to conceptualise language independently. CDS or child-directed
speech is commonly known as "baby talk" in everyday life and includes changes such as
slower rate, exaggerated intonation, higher voice, more obvious intonations for different
types of speech (i.e., questions, statements, orders), high frequency, repetition, simple
syntax and concrete vocabulary. These strategies all simplify language to make it as easy as
possible for the child to understand and to maximise phonemic contrasts and pronunciation
of correct forms.

Vygotsky also developed the concepts of private speech to name situations when children
must speak to themselves in a self guiding and directing way – initially out loud and later
internally and the zone of proximal development which refers to the tasks a child is unable
to complete alone but is able to complete with the assistance of an adult.

Jerome Bruner introduced the term Language Acquisition Support System (LASS), which
refers not only to the child`s immediate envorinment of adults but also, in the fuller sense to
the culture, in which a child was born. Such network of adults (or "more-knowledgable
others") that interact with a young child supports that child's language development.