Juurvorm

Juurvorm is the root form of a word that serves as the base for all its inflected variants. It is the form most closely linked to the word’s core meaning and is typically used as the lemma in dictionaries and corpora. In Estonian linguistic practice, juurvorm is the form to which inflected endings are attached, and from which other derived forms are generated.

In natural language processing and language teaching, juurvorm is the item a lemmatizer returns when it analyzes a word. It stabilizes indexing and search by grouping all inflected forms under one lemma. For Estonian nouns, the juurvorm often corresponds to the nominative singular; for verbs, to the infinitive; for adjectives, to the base adjective form. The concept differs from stemming, which may reduce a word to a shorter, non-dictionary form.

Examples help illustrate the idea. The noun koer (dog) is the juurvorm for koer, koera, and koerad, showing how inflected forms connect to the same base. The verb kirjutama (to write) is the juurvorm; its inflected forms include kirjutan, kirjutad, kirjutab. The adjective ilus (beautiful) has the juurvorm ilus, with inflected variants like ilus, ilusa, ilusaid.