Comparative reconstruction is a method used in historical linguistics to infer the features of a language that is no longer spoken. By comparing similarities and differences among related languages, linguists can identify common elements and reconstruct aspects of their ancestor language. This process often involves analyzing vocabulary, grammar, and phonetics across languages within a language family, such as the Indo-European languages. This technique relies on the principle that languages evolve over time, leading to systematic changes. By examining cognates—words in different languages that have a common origin—researchers can deduce the characteristics of the ancestral language. For example, the reconstruction of the Proto-Indo-European language has provided insights into the linguistic features of many modern languages.