Perusmuodot

Perusmuodot, or base forms, are the basic lemma forms of words in Finnish grammar. They serve as the canonical representation of a word from which all inflected forms are derived and are often used as the entry form in dictionaries and language processing. The concept applies across parts of speech and is central to Finnish morphology and lexicography.

For verbs, the common perusmuoto is the active infinitive, for example kirjoittaa “to write.” From this form, additional finite forms such as kirjoitan, kirjoitat, kirjoittaa, and other conjugations are produced. While Finnish has several non-finite verb forms, the active infinitive is frequently treated as the verb’s perusmuoto in linguistic and educational contexts.

For nouns, the perusmuoto is typically the nominative singular form, such as koira “dog.” Other cases and plural forms are generated from this base through declension. For adjectives, the perusmuoto is usually the positive form in nominative singular, for example suuri “big,” from which comparative and superlative forms are derived.

In practice, perusmuodot are essential for lemmatization and lexicographic organization. They allow inflected or derived forms to be grouped under a single lemma, facilitating dictionary lookup, natural language processing, and linguistic analysis. The concept helps clarify how a word’s various surface forms relate to a single underlying form, even as specific endings and structures change with grammar, tense, mood, case, number, and degree.