"Comparative linguistics, or comparative-historical linguistics (formerly comparative philology) is a branch of historical linguistics that is concerned with comparing languages to establish their historical relatedness.
Genetic relatedness implies a common origin or proto-language and comparative linguistics aims to construct language families, to reconstruct proto-languages and specify the changes that have resulted in the documented languages. To maintain a clear distinction between attested and reconstructed forms, comparative linguists prefix an asterisk to any form that is not found in surviving texts. A number of methods for carrying out language classification have been developed, ranging from simple inspection to computerised hypothesis testing. Such methods have gone through a long process of development." - (en.wikipedia.org 09.01.2021)
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