How Loans Are Adapted

Finnish is an agglutinative language, meaning it attaches endings to words. To do this, a word must have a vowel stem. Loanword adaptation follows three main paths:

1. General Loans (Yleislainat): These are old loans fully integrated into Finnish. They often simplify consonant clusters (e.g., Swedish strand -> ranta) and follow consonant gradation.

2. Special Loans (Erikoislainat): Modern loans that keep foreign letters (b, g, f, d) but follow Finnish grammar. Unlike old loans, they typically retain initial consonant clusters (e.g., stressi, professori). If they end in a consonant, an epenthetic -i is added (e.g., film -> filmi). The final consonant is often doubled (e.g., bussi, malli, tonni) to preserve the short-vowel rhythm and syllable weight of the source word.

3. Vowel Harmony: Suffixes must match the word's vowels. In loanwords, the last non-neutral vowel (a, o, u, ä, ö, y) usually determines the harmony of the suffix (e.g., amatööri -> amatöörissä). If a word contains only neutral vowels (e, i), it takes a front-vowel suffix (e.g., peli -> pelissä). Words with back vowels take back-vowel suffixes (e.g., tomaatti -> tomaatissa). However, disharmonic loanwords with a strong back vowel followed by a front vowel often cause hesitation, and variation is accepted in practice (e.g., analyysissä vs. analyysissa). In compound words, the last word determines the vowel harmony (e.g., jääkaappi -> jääkaapissa). Also, vowel harmony is based on Finnish pronunciation, not foreign spelling (e.g., jazz, pronounced with back-vowel a in Finnish, approximately jats, → jazzissa).

4. Consonant Gradation: While old loans like katu (street) gradate (kadun), many modern loans like auto (car) do not (auton). Because modern loans resist qualitative changes that would make them unrecognizable, they generally only undergo quantitative gradation (shortening double stops like pp, tt, kk to single stops, e.g., pankki -> pankin). Single foreign consonants usually remain stable; however, adapted verbs and some newer loans can have quantitative alternations such as bb → b and gg → g. Consult the established word paradigm. The quantitative alternation kk → k occurs in pankki → pankin. Do not infer a missing mp → mm alternation from kompassi: its p is not in the final stem syllable affected by adding the ending. Finally, consonant clusters ending in a stop (like st, sk, tk) block gradation (e.g., posti -> postin); this is a universal rule of Finnish phonotactics that applies to native words just as strictly.

Citation Loans and Foreign Names
A citation loan (sitaattilaina) keeps its foreign spelling. When the spelling ends in a consonant but Finnish pronunciation ends in a vowel, an apostrophe separates the ending: show’ssa. This is not a rule to add an apostrophe to every foreign word. Foreign names usually keep their written consonants unchanged when inflected, as in Davidin; abbreviations follow their own letter-by-letter or word-like pronunciation and ending rules.