The historical method of cognition includes various types. Using various methods, knowledge of phenomena is realized to one degree or another.
The comparative historical method is a scientific method by which the “general” and “special” in phenomena are determined. With the help of it, different stages of development of two different or the same phenomenon are known.
The comparative historical method makes it possible to identify and compare the changes that have occurred in the development of the object of study, as well as determine the direction of further progress.
Experts classify several subspecies of this method of cognition. So, there is a comparative method (revealing the nature of objects), historical-typological (explaining the similarity of phenomena not related by origin in terms of developmental conditions and genesis), historical-genetic (studying and determining similarity on the basis of kinship by origin). The method of cognition is also distinguished, in which the mutual influences of various phenomena are evaluated.
The comparative historical method is a set of techniques by which they prove the kinship of some languages and restore facts from the history of their development. This method of cognition was created in the 19th century. Its founders are outstanding scientists (Alexander Vostokov, Jacob Grimm, Franz Bopp, Rasmus Raek).
Some languages may contain similar words. This is due to borrowing. There are also those that rarely move from one language to another. These include, for example, adjectives that indicate the simplest signs, names of body parts and so on. The endings of bowed and conjugated words do not pass from one language to another. However, they are often similar. According to the researchers, the reason is that these endings are the result of the development of a single word, and the languages themselves in which they exist are descendants of the same "proto-language".
The comparative historical method includes several research methods.
An external reconstruction technique is often used. It represents the identification of genetically identical words and morphemes in related languages. At the same time, they reveal the results of regular changes in the sounds of the source language. In addition, a method is used to construct a hypothetical proto-language model and rules for deriving certain morphemes in descendants. When a sufficiently large number of related morphemes and a not very complex phonetic history of descendants are preserved, the results of sound changes act as correspondences between related languages. In another case, the identification of sound changes is possible only during the reconstruction of intermediate stages of development. In this case, the proto-languages of groups and subgroups in the family of languages are investigated .
The technique of internal reconstruction is also used. In this case, correlations and phenomena are revealed in the structure of a particular language that clearly indicate that there are some components of the system in the early stages of its development.
There is a method of comparative analysis of borrowed words.
In some cases, researchers extract information from toponymy data. At the same time, the resulting reconstructions concern all aspects of the language system: morphology, phonology, vocabulary, morphology, syntax (to some extent). At the same time, the obtained models cannot be identified directly with a real-life parent language. Educated reconstructions reflect only information about him, which will be inevitably incomplete, due to the inability to recreate phoneme contrasts, roots, etc., which disappeared in all subsequent languages.