Pääsanana

Pääsanana is Finnish for headword or lemma, a term used in linguistics and lexicography to describe the form of a word that serves as the canonical entry under which all related inflected forms are listed. The concept helps organize dictionaries and word lists by providing a stable reference form for each word.

Etymologically, pääsanana is a compound of pää meaning head and sana meaning word. In practice, the pääsanana is the form chosen as the reference for a given lexeme. For nouns, this is usually the singular nominative; for verbs, the infinitive; for adjectives, the nominative singular. Some languages or resources may treat particularly irregular words or proper names with special conventions, but the general idea remains consistent: the pääsanana is the form used to index and cite the word.

In usage, a word such as talo (house) has inflected forms like talon, taloa, talossa, taloja, etc., while its pääsanana is talo. For a verb like kirjoittaa (to write), the lemma is kirjoittaa, with many conjugated forms such as kirjoitan, kirjoitit, kirjoitetaan. The pääsanana thus functions as the reference form for lookup, sorting, and cross-referencing within lexicographic works and language-processing tasks.

Pääsanana is central in both education and computational linguistics, where it supports morphology generation, search algorithms, and data organization. See also lemma, lexicon, inflection, and morphology.