Languages are ever changing. They may evolve in many aspects, including how we pronounce a word, how we express a concept, what we mean by saying what, or how we structure a sentence. Essentially, how languages differ (‘synchronic’ perspectives of linguistics) can be put onto a timeline and examined over time to see how languages used in the past differ from the present (‘diachronic’ perspectives).
Language change can be generally triggered by two types of factors—internal factors and external factors.
Internal factors refer to those related to language itself, such as the tendency to simplify pronunciation (e.g., from ‘did you’ to ‘diju’) or to generalise grammatical features (e.g., from ‘foci’ to ‘focuses’). Contact with other languages is another major factor that may cause a language to change. Languages may borrow words from each other or further evolve into a new language, such as Kriol.
Major external factors, or non-linguistic factors, include geography and social factors. For example, geographical barriers are likely to block contact between speech communities. These languages/dialects would thus not only have minimal influence from each other but possibly evolve into more distinct varieties on their own. Just listen to modern Australian English(es) and you will notice how it’s (they’re) different from the British root!
Speaking of social factors that may largely affect languages, we usually discuss age, gender, socioeconomic status, neighbourhood and ethnicity. Usually, people adjust the way we speak according to our identification, whether consciously or unconsciously. That is, speakers may articulate certain sounds or use certain expressions distinct to the group that they identify with, while avoid utter something distinct to another group that they don’t wish to be associated with. This tendency then leads to language change over time when, for example, young people don’t want to sound like their parents!
To study language change, linguists describe linguistic features observed in different time periods. We sometimes record history of words (‘etymology’) or differences across regions (‘dialectology’). Based on studies over time, historical linguists look for general tendencies of change, and from there, we can possibly reconstruct our ancestors’ languages and the prototypical language of a language family.
Linguists are also interested in the relation between human cognition and language change. The field of psycholinguistics investigates how our brain processes languages, including acquisition, comprehension and production. By adopting diachronic approaches, we hope to contribute to greater understanding of human cognition in the process of evolution.
With increasing technological supports today, we can easily utilise corpora to collect and organise large amount of linguistic data on electronic devices. For instance, we can analyse a linguistic feature of interest that occurs on different online platforms over a time period.
Aside from the long history of language change in the past, languages will of course keep on evolving. Read more about how languages evolve in the era of the Internet and for more interesting purposes in the pages below: Language on the Internet and Conlangs.
Videos: On linguist Jürgen Handke’s the Virtual Linguistics Campus channel, he explains types of language change (part 1 part2 with Natalie Kiesler) and reasons for language change. If you are interested in the history of English, Handke also did an overview of it (listen to Old English, Middle English and Early Modern English used by Shakespeare!).
Book: Sociolinguistics: An Introduction to Language and Society (4th edition) by Peter Trudgill (2001).