Editing Historical linguistics (section)

== Diachronic and synchronic analysis ==
{{Further|Diachrony and synchrony}}
In linguistics, a '''synchronic analysis''' is one that views linguistic phenomena only at a given time, usually the present, but a synchronic analysis of a historical language form is also possible. It may be distinguished from diachronic, which regards a phenomenon in terms of developments through time. Diachronic analysis is the main concern of historical linguistics. However, most other branches of linguistics are concerned with some form of synchronic analysis. The study of language change offers a valuable insight into the state of linguistic representation, and because all synchronic forms are the result of historically evolving diachronic changes, the ability to explain linguistic constructions necessitates a focus on diachronic processes.<ref>Bybee, Joan L. "Diachronic Linguistics." The Oxford Handbook of Cognitive Linguistics, June 2010.</ref>

[[File:Ferdinand_de_Saussure_by_Jullien_Restored.png|thumb|right|alt=Swiss linguist Ferdinand de Saussure|Swiss linguist Ferdinand de Saussure]]
Initially, all of modern linguistics was historical in orientation. Even the study of modern dialects involved looking at their origins. [[Ferdinand de Saussure]]'s distinction between [[synchronic analysis (linguistics)|synchronic]] and diachronic linguistics is fundamental to the present day organization of the discipline. Primacy is accorded to synchronic linguistics, and '''diachronic linguistics''' is defined as the study of successive synchronic stages. Saussure's clear demarcation, however, has had both defenders and critics.

In practice, a purely-synchronic linguistics is not possible for any period before the invention of the [[gramophone]], as written records always lag behind speech in reflecting linguistic developments. Written records are difficult to date accurately before the development of the modern [[title page]]. Often, dating must rely on contextual historical evidence such as inscriptions, or modern technology, such as [[carbon dating]], can be used to ascertain dates of varying accuracy. Also, the work of [[sociolinguists]] on linguistic variation has shown synchronic states are not uniform: the speech habits of older and younger speakers differ in ways that point to language change. Synchronic variation is linguistic change in progress.

Synchronic and diachronic approaches can reach quite different conclusions. For example, a [[Germanic strong verb]] (e.g. English ''sing'' ↔ ''sang'' ↔ ''sung'') is [[regular verb|irregular]] when it is viewed synchronically: the [[neurolinguistics|native speaker's brain processes]] them as learned forms, but the derived forms of regular verbs are processed quite differently, by the application of productive rules (for example, adding ''-ed'' to the basic form of a verb as in ''walk'' → ''walked''). That is an insight of [[psycholinguistics]], which is relevant also for [[second language acquisition|language didactics]], both of which are synchronic disciplines.  However, a diachronic analysis shows that the strong verb is the remnant of a fully regular system of internal vowel changes, in this case the [[Indo-European ablaut]]; historical linguistics seldom uses the category "[[irregular verb]]".

The principal tools of research in diachronic linguistics are the [[comparative method]] and the method of [[internal reconstruction]]. Less-standard techniques, such as [[mass lexical comparison]], are used by some linguists to overcome the limitations of the comparative method, but most linguists regard them as unreliable. The findings of historical linguistics are often used as a basis for hypotheses about the groupings and movements of peoples, particularly in the prehistoric period. In practice, however, it is often unclear how to integrate the linguistic evidence with the [[archaeological]] or [[genetics|genetic]] evidence. For example, there are numerous theories concerning the homeland and early movements of the [[Proto-Indo-Europeans]], each with its own interpretation of the archaeological record.