Diachronic study is the historical study of language. Diachronic is contrasted with synchronic which is the study of language at the present time. Diachronic is the study of language that studies how language changed or evolved over time. So diachronic study is synonymous with historical study. It takes the history of language into account.
Diachronic Changes in English:
English have observed changes on all the linguistic levels i.e. phonetics, in phonology, in morphology, in syntax, in semantics. English today is totally different from what it was a thousand years ago.
What types of changes a languages can undertake?
A language can undertake the following changes both synchronically (changes happening at present) and diachronically (changes happened in the past, historically).
1.Change in sound
2. change in meaning
3. change in morphology
4. change in grammar/syntax
English has observed sound changes. These changes are said to be related with the following processes;
- Monophthongization: in which dipthongs become monophthongs.
- Diphthongization: in which monophthongs become diphthongs. For example, in past English it hus (house), while in present English it is hause (house).
- Metathesis: in metathesis, the sounds of the words are rearranges. Therefore, the word “butterfly” used to be “flutterby”.
- There are also changes in vowels which are related to lowering/heightening of vowels and fronting/backing of vowels.
Changes in Vocabulary:
Almost eighty percent of the words of Old English were lost in by the time of Middle English period. Similarly many words from the period of Middle English have been lost in the present day English. New words are showing up, for example selfie. This word did not exist a decade ago.
Changes in Meaning:
Other than changes in sound and vocabulary, English has received changes in its meanings too.
For example, the word “awful” originally had the meaning of “inspiring wonder” but now it has negative meaning.
In many cases the meanings of words become generalized and in other cases the meanings of words become specific. Therefore, the semantic change can take the form of narrowing or widening, degeneration, and amelioration.
Changes in syntax or Grammar:
Syntactic changes were also observed in English. Syntactic changes are related to the changes in the structure of sentence of word order. In other words it is the change in grammar. For example, in old English there was no use of “did” in sentences like “if I did not know”.