cognats

Cognates, sometimes spelled cognats in informal contexts, are words in different languages that share a common etymological origin, usually traced to a reconstructed ancestor language such as Proto-Indo-European or Proto-Germanic. The term cognate is used in historical and comparative linguistics to describe such related vocabulary. In modern languages, cognates often resemble each other in form and meaning because they descend from a shared root, even though the words may have diverged in pronunciation and spelling.

The identification of cognates relies on the comparative method: regular correspondences in sounds and core meanings across a language family point to a common source. Cognates can link languages as closely related as English and German, or more distantly related languages within a broader family. They are central to reconstructing proto-languages and to classifying languages into families.

Examples common in many Indo-European languages include English mother, German Mutter, and Dutch moeder, all derived from Proto-Germanic *mōdēr. Another set is English father, German Vater, Dutch vader, from Proto-Germanic *fader. A third example is water, Wasser, and water, traced to Proto-Germanic *watar, with the modern forms differing due to language-specific sound changes.

Not all similar forms are cognates; some are loanwords borrowed between languages, and others are false cognates that look related but do not share a recent common origin. Cognates therefore illuminate historical connections while requiring careful evidence.

Significance: Cognates underpin the reconstruction of proto-languages and the mapping of language families, and they assist language learners and scholars in recognizing related vocabulary across languages.