1. WHAT IS SOCIOLINGUISTICS?
Sociolinguistics is a term including the aspects of linguistics applied toward the connections between language and society, and the way we use it in different social situations. It ranges from the study of the wide variety of dialects across a given region down to the analysis between the way men and women speak to one another. Sociolinguistics often shows us the humorous realities of human speech and how a dialect of a given language can often describe the age, sex, and social class of the speaker; it codes the social function of a language.

2. Standard English
This is the variety which forms the basis of printed English in newspapers and books, which is used in the mass media and which is taught in schools. It is the variety we normally try to teach to those who want to learn English as a second language.

3. Accent & Dialect
The term accent, when used technically, is restricted to the description of aspects of pronunciation which identify where an individual speaker is from, regionally or socially.
It is to be distinguished from the term dialect which describes features of grammar and vocabulary, as well as aspects of pronunciation.

4. Dialect atlas The noun dialect atlas has one meaning:
an atlas showing the distribution of distinctive linguistic features   Synonym: linguistic atlas

5. Isogloss
A geographic boundary line delimiting the area in which a given linguistic feature occurs.
An isogloss is the geographical boundary of a certain linguistic feature, e.g. the pronunciation of a vowel, the meaning of a word, or use of some syntactic feature.

6. Dialect continuum
A dialect continuum is a range of dialects spoken across a large geographical area, differing only slightly between areas that are geographically close, and gradually decreasing in mutual intelligibility as the distances become greater. Dialects separated by great geographical distances may not be mutually comprehensible.

7. Mutual intelligibility
In linguistics, mutual intelligibility is a property exhibited by a set of languages when speakers of any one of them can readily understand all the others without intentional study or extraordinary effort. It is sometimes used as one criterion for distinguishing languages from dialects, though sociolinguistic factors are also important.

8. Diglossia
A sociolinguistic phenomenon in which complementary social functions are distributed between a prestigious or formal variety and a common or colloquial variety of a language, as in Greek, Tamil, or Scottish English.
In linguistics, diglossia is a situation where, in a given society, there are two (often) closely-related languages, one of high prestige, which is generally used by the government and in formal texts, and one of low prestige, which is usually the spoken vernacular tongue. The high-prestige language tends to be the more formalised, and its forms and vocabulary often 'filter down' into the vernacular, though often in a changed form.

9. Sociolect
In linguistics, a sociolect is the language spoken by a social group, social class or subculture. It is a portmanteau term combining the words "social" and "dialect", which in this regard differs from an idiolect – which is the form of a language peculiar to an individual – and a dialect, which is a form of speech peculiar to a certain area. However, dialects often have a particular social status, so that a given variant may be considered simultaneously a dialect and a sociolect. For example, standard Italian is a dialect in that it is particular to Tuscany; yet, being the national language of Italy, it is also a sociolect in that it carries a certain prestige from being a lingua franca throughout the country – both in broadcasting, in the press and by people of high social status.

10. Idiolect
The speech of an individual, considered as a linguistic pattern unique among speakers of his or her language or dialect.
An idiolect is a variety of a language unique to an individual. It is manifested by patterns of word selection and grammar, or words, phrases, idioms, or pronunciations that are unique to that individual. Every individual has an idiolect; the grouping of words and phrases is unique, rather than an individual using specific words that nobody else uses.

11. Lingua Franca
It implies a common, or standard, language. The term is used in the information industry to refer to the most-widely used format, protocol or command language for a particular purpose. Its actual meaning is "Frankish language," which is spoken in various Mediterranean ports and is a combination of Italian, Spanish, French, Greek, Arabic and Turkish. Its original meaning also implies a hybrid or mixture of languages.

12. Code-switching
Code-switching is a term in linguistics referring to alternation between two or more languages, dialects, or language registers in the course of discourse between people who have more than one language in common. Sometimes the switch lasts only for a few sentences, or even for a single phrase.
The switch is commonly made according to the subject of discourse, but may be for a variety of other reasons such as the mood of the speaker. For example, a person might swear only in French.

13. Jargon
A special language belonging exclusively to a group, often a profession. Engineers, lawyers, doctors, tax analysts, and the like all use jargon to exchange complex information efficiently.

14. Slang
Non-standard vocabulary of extreme informality, usually not limited to any region. It includes newly coined words, shortened forms, and standard words used playfully out of their usual context. Slang is drawn from the vocabularies of limited groups: cant, (the special speech of a group with low social standing i.e. gypsies) the words or expressions coined or adopted by an age, ethnic, occupational, or other group (e.g., college students, jazz musicians); jargon, the shoptalk or technical terminology specific to an occupation; and argot, the cant and jargon used as a secret language by thieves or other criminals.

15. Monolingualism, Bilingualism
Monolingualism: Using or knowing only one language.
Ability to speak two languages. It may be acquired early by children in regions where most adults speak two languages (e.g., French and dialectal German in Alsace). Children may also become bilingual by learning languages in two different social settings; for example, British children in British India learned an Indian language from their nurses and family servants. A second language can also be acquired in school. Bilingualism can also refer to the use of two languages in teaching, especially to foster learning in students trying to learn a new language. Advocates of bilingual education in the U.S. argue that it speeds learning in all subjects for children who speak a foreign language at home and prevents them from being marginalized in English-language schools.

16. Multilingualism
A multilingual person, in the broadest definition, is anyone who can communicate in more than one language, be it active (through speaking and writing) or passive (through listening and reading). More specifically, the terms bilingual and trilingual are used to describe comparable situations in which two or three languages are involved.
Multilingualism could be rigidly defined as being native-like in two or more languages. It could also be loosely defined as being less than native-like but still able to communicate in two or more languages.