I. sociolinguistics:
Sociolinguistics is the study of patterns and variations in language within a society or community. In other words, it is the study of language in relation to social factors (e.g., social class, region, age, sex, national identity, rank). We can distinguish the speaker from his speaking (e.g., the Scottish pronounce the phoneme /r/ in words like car). Other sociolinguists focus on what happens when speakers of different languages interact. The goal of sociolinguistics is to understand communicative competence--what people need to know to use the appropriate language for a given social setting.
II. Psycholinguistics :
Psycholinguistics merges the fields of psychology and linguistics to study how people process language and how language use is related to underlying mental processes. Put differently, it is the study of the cognitive processes that support the acquisition and use of language. The scope of psycholinguistics includes language performance at normal circumstances and when it breaks down. Historically, the focus of most psycholinguistic studies has been on L1 acquisition, comprehension and production. But recently, the focus is on second-language acquisition. Psycholinguists also study language disorders such as aphasia (impairment of the ability to use or comprehend words) and dyslexia (impairment of the ability to make out written language).
III. Computational Linguistics :
Computational linguistics involves the use of computers to compile linguistic data, analyze languages, translate from one language to another, and develop and test models of language processing. Computers also aid in the construction of dictionaries and concordances.
IV. Applied Linguistics :
Applied linguistics employs linguistic theory and methods in teaching and in research on learning a second language. It also looks at the errors people make as they learn another language, and tries to understand what happens in the mind of the learner.
V. Anthropological Linguistics :
Anthropological linguistics uses linguistic approaches to analyze culture. Anthropological linguists examine the relationship between a culture and its language, the way cultures and languages are related to one another.
VI. Philosophical Linguistics :
Philosophical linguistics examines the philosophy of language. Philosophers of language search for the grammatical principles and tendencies that all human language share. Among the concerns of linguistic philosophers is the range of possible word order combinations throughout the world (e.g., 95% use [SVO] order, 5% use [SOV] or [VSO] order).
VII. Neurolinguistics :
Neurolinguistics is the study of how language is processed and represented in the brain. Neurolinguists seek to identify the parts of the brain involved with the production and understanding of language and to determine where the components of language (phonemes, morphemes, and structure or syntax) are stored.