perusmuodoksi

Perusmuodoksi is a Finnish linguistic term meaning “to the base form” or “as the base form.” It denotes the lemma or dictionary form of a word—the canonical form used to represent all of its inflected variants. In Finnish lexicography, the perusmuoto is the form that is cited as the lemma: for nouns, typically the nominative singular; for verbs, the infinitive; for adjectives, the basic positive form. Grammatically, perusmuodoksi is the translative case of the noun perusmuoto, literally “into the base form,” and is used when discussing conversion to this form.

The concept is central in dictionaries, language teaching, and computational linguistics. It provides the reference point for analyzing morphology, indexing entries, and performing lemmatization in natural language processing. By reducing a word’s various inflected forms to its perusmuoto, tools and learners can recognize that different appearances share the same underlying form.

Examples help illustrate the idea. The noun talo has inflected forms such as talossa (in the house) or taloon (into the house); its perusmuoto is talo. The verb kirjoittaa has inflected forms like kirjoitan (I write) or kirjoitti (wrote); its perusmuoto is kirjoittaa. Understanding perusmuodoksi aids in organizing vocabulary and in computational tasks that require normalization of word forms. See also lemma, lemmatization, and Finnish morphology.