In linguistics, the academic study of human language, it often appears that a monolithic concept of language is being assumed. However many linguists believe that this is an idealisation which may be appropriate for certain purposes, but for the most part conceals the underlying facts. Namely:

Each language is made up of multiple, coalescing objects

• For sociolinguists, languages are located in social groups, contexts and practices. No two of these are identical, and no individual or group uses the same practices in all contexts. From this perspective, there are as many Englishes as there are groups of users, multiplied by the different contexts and practices in which they use its resources.

• For psycholinguists, languages are located in the minds and brains of all those who use them. No two versions are identical. In this sense, then, there are perhaps over two billion Englishes: a different one in the brain of every user.

• In the same way that gravity brings into being galaxies by connecting billions of separate objects, individual acts of (effective) communication connect complex sets of linguistic knowledge (and use) that we think of as ‘English’.

 
Each language has fuzzy boundaries

• People have always moved and language has always moved with them. With globalisation, this mobility has accelerated dramatically, and with the technological advances that have accompanied globalisation, language now also moves while people stay in one place (via social media and the Internet, for example). The result is unprecedented language distribution across the globe.

• When people move, their language forms and practices change. They gradually become distinct from those of users who stayed behind or moved to other locations. They can also become influenced strongly by the language forms and practices of the new people they interact with, to the extent that it’s not clear where one language stops and the other starts. For very mobile languages, the result is massive variation and unclear boundaries.

• Bilingualism (and increasingly multilingualism) is the norm. Typical bilinguals use some parts of one language for certain purposes (e.g. at home), and some parts of another language for other purposes (e.g. in school). Often they switch from one language to the other as the dynamics of an interaction change. A bilingual’s resources in one of their languages might appear incomplete when compared with those of a monolingual of a similar socioeconomic and educational profile, but their overall communicative repertoires (what they can do with both languages combined) will be more or less equivalent. So the boundaries between languages in the heads of speakers tend not to be fixed either.

 
Each language has an ambiguous shape and form

• Linguists have produced detailed grammatical descriptions for only a fraction of the world’s languages, and even for the most closely studied languages (of which English is perhaps the best example), there are no complete, unified accounts of the knowledge that any given native speaker might possess.

• No dictionary contains all the words known by those who would identify as speakers of a particular language. New words are being used on a daily basis, frequently by multilinguals, and often they are never used again.

 
Each language is variable, hybrid, and dynamic

• Languages embrace enormous variability at every level of form and function. Although many people think of a language as having a single ‘standard’ form, most users don’t actually know it (fully) or use it (most of the time, if ever). Languages are used with local accents and dialects (regional differences in pronunciation, vocabulary and grammar), a continuum of contextual styles or registers (e.g. from formal to informal), and diverse patterns of form and use associated with social factors (e.g. occupation, gender, age, ethnic and cultural identity, socioeconomic status, educational level).

• When users of one language come into contact with users of other languages, they exchange words. This can be the result of invasion, conquest, enslavement, exploration, trade, migration, education, marriage, literature, science, religion, technology, fashion, political dissent, popular music, movies, back-packing, … or whatever. Many of these words are absorbed into the language repertoire of those involved. Every language is a hybrid, absorbing multilingual resources, and those that have been very mobile, like English, are becoming increasingly mixed in composition.

• Learning and using a language can change that language in tiny ways. When combined together and spread across individuals, such changes can be perceived historically as turning one language into another. So, for example, we know that Latin dialects became Italian, French, Spanish, etc., and that Sanskrit dialects became Hindi, Punjabi, Bengali, etc. But it is impossible to put a date on when any language was born, because: (a) a language is not one system but many related systems; and (b) these systems have evolved gradually from generation to generation, in a continual process that started when members of our species first began to speak. Language is forever in motion.