Suffixið

Suffixið is the Icelandic term for the suffix, a morpheme that attaches to the end of a word to modify its meaning or grammatical function. Suffixes can be inflectional, marking grammatical categories such as number, case, tense, mood, or definiteness, or derivational, creating new words or shifting the word’s part of speech.

In Icelandic grammar, suffixes play a central role in word formation and agreement. Nouns often carry a definite suffix, which marks definiteness directly on the noun. For example, bók (book) becomes bókin (the book) with the suffix -in; hús (house) becomes húsið (the house) with the suffix -ið; dagur (day) becomes dagurinn (the day) with the suffix -inn. Adjectives and verbs also use suffixes to agree with the gender, number, and case of nouns, as well as to indicate tense, mood, or voice in verbal forms. Derivational suffixes can create nouns from verbs or adjectives, or form new adjectives and participles, expanding the lexicon through affixation.

Suffixið is a widespread feature beyond Icelandic, underlying the morphology of many languages that rely on suffixation to encode grammatical relationships and word formation. In Icelandic, as in related Nordic languages, suffixes enable compact expression of definiteness, number, and inflection, making suffixation a fundamental aspect of the language’s structure.