þekkist

Þekkist is a historical inflected form of the Norse-Icelandic verb þekkja, meaning “to know” or “to recognize.” The form is associated with the second-person singular and is analyzed in some grammars as belonging to the middle voice, a category used in Old Norse grammar to express reflexive or stative nuance. In this analysis, þekkist would be used in contexts where the subject is involved in the result or experience of the action, roughly corresponding to a sense like “you are known” or “you recognize yourself,” depending on context. It coexists with active forms such as þekkir (you know) and is generally treated as a more archaic or literary variant.

In practice, þekkist appears in medieval texts and is discussed in grammars as an example of how Norse verbs could form middle-voice present-tense forms. The form is largely attested in Old Norse and Old Icelandic sources, including sagas and poetry, though it is not productive in modern Icelandic. Its use illustrates historical verb morphology and the broader system of voice and mood in the classical North Germanic languages.

Modern Icelandic no longer uses þekkist; contemporary forms for “you know” are expressed with the active þekkir. Today, þekkist is primarily of interest to linguists and philologists studying Old Norse grammar, verb morphology, and the development of Icelandic. See also þekkja, Old Norse grammar, and Icelandic language.