Functional linguistics or Functionalism - Behaviourism - Structuralism - Functions of language proposed by Micheal Halliday. - Generative Grammar - GENERATIVISM - Sign, Signified, and Signifier -

Why do we have different schools of thoughts in Linguistics?

When different scholars give different interpretations based on their research and studies about a particular subject, different schools of thought are born as a result. The main objective of all the schools of thought and their scholars remains the same, which is to reach a logical and correct answer. The methods that they apply or the generalisations that they come up with give rise to different schools of thoughts.

Behaviourism:

Behavioural theory of behaviourism is one of the schools of thought in psychology. According to this theory, we humans are born with a clean slate of brain known as "tabula rasa", and  all learning, including language, is possible through exposure to the environment. This theory was put by one of the psychologists B.F Skinner and further contributions were also made by others.

Transformational Generative Grammar is a model of grammar associated with the school of GENERATIVISM, put forth by Noam Chomsky. TGG makes the claim that sentences consist of three components: Semantic, which is associated with Deep Structure, phonological, associated with Surface structure, and Transformational component, which is associated with transforming the deep structure into surface structure. TGG is a set of rules that help speakers to generate correct sentences and  use basic sentences to create new unlimited sentences by changing, moving, and adding new components in the sentences. So, TGG transforms deep sentences into surface sentences; it was first introduced in 1957 by Noam Chomsky in his book Syntactic Structures. 

Structuralism.

Structuralism is one of the schools of thoughts in Linguistics. It was put forth by Swiss-linguist Ferdinand de Saussure in the 1950's. Saussure made an attempt to explain how language works by focusing on a non-historical approach rather than historical approach that had been focused on by other linguists at that time. According to Saussure, languages consist of different units (signs) that can only be understood by relating them to other (signs) that assist us in understanding the units. In simple words, in order to understand an object you need to understand how it relates to other things, for example a pair of headphones can be understood by understanding its relation to other things linked to it like music, video, podcast, and phone call.

Sign, Signified, and Signifier.

According to Swiss-linguist Ferdinand de Saussure, languages consist of signs, and sign consists of two constituents (Signifier and Signified). Signifier means name, sound, or image of any object. Whereas Signified means the concept of that object the Signifier is referring to. 

GENERATIVISM:

This school of thought in Linguistics was put forth by American-linguist Noam Chomsky. Chomsky tried to explain how humans acquire language; furthermore, his approach evolved, and explained that the basic rules of all the languages are the same. This approach led him to the theory of Universal Grammar U.G. 

Generative Grammar:

Generative Grammar is a model of grammar which focuses on how we create an infinite number of sentences from a finite set of rules. 

Functions of language proposed by Micheal Halliday.

Micheal Halliday belongs to the Copenhagen School. He sees language as a social and cultural phenomenon like Ferdinand de Saussure and unlike Noam Chomsky who sees language as a biological phenomenon. 

The seven functions that he proposed are based on the study of his son who was at that time acquiring language. 

The first 4 functions help children to express their needs or desires. 

Instrumental: This function helps children to express their needs or desires. For example, I need candy.

Regulatory: This function is used to ask people to do something. For example, go away, pick me up.

Interactional: Interpersonal function helps children to build relationships and make contact. For example, love you mummy.

Personal: This function is used to express feelings or thoughts children have with people around them. For example, Me good girl. 

The last 3 functions help children to get to know their environment.

Heuristic: This function helps them to understand and gain knowledge about the environment around them.

Imaginative: This function is used to tell jokes, stories and imaginary things. 

Representational: This function is used to give information or facts to the people around them.

Functional linguistics or Functionalism.

It is one of the well-known schools of thought in Linguistics. It is concerned with functions of a language. It describes that these functions serve the purpose of expressing meanings, and these meanings can be modified or changed as per the context.

In Europe, there were two emerging schools of thought in Functionalism: The Prague School and The Copenhagen School.

The Prague School was dominated by the scholars of Prague, one of the scholars of The Prague School was Jakobson who gave his interpretation of functions of a language. According to him, language has 6 functions: referential, aesthetic or poetic, phatic, metalingual, conative, and expressive. 

Referential Function: This function of language is used to convey information to the audience about something the speaker is referring to. For example, It is a sunny day today. 

Emotive Function: It is also known as expressive function. It is used for expressing feelings or emotions by the sender for example, She is happy about her promotion.

Conative Function: This function focuses on the receiver. We use this function to get the attention of or reaction of the addressee for example, pass me the glass of water or you two have to leave immediately.

Phatic Function: This function helps us to build social relations with people by greeting or saying farewell. It is not concerned with how people carry out conversations or gossip about something.

Poetic Function: This function is also known as aesthetic function. We use this function to convey our message in a poetic way or in colloquial manner. For example, life is not a bed of roses.

Metalingual Function: This function focuses on whether the addresser and the addressee have the same language (code).