äänenvaihtelua

Äänenvaihtelu refers to the phenomenon of vowel alternation in Finnish. It is a systematic and predictable change in a word's vowel, often occurring in the stem of a word when grammatical suffixes are added. This alternation is a fundamental aspect of Finnish morphology and is crucial for understanding word formation and pronunciation.

There are two main types of äänenvaihtelu: strong and weak. The strong alternation typically involves a longer or more open vowel in the uninflected or basic form of the word, which changes to a shorter or more closed vowel when a suffix is attached. Conversely, the weak alternation involves a shorter or more closed vowel in the basic form, changing to a longer or more open vowel in the inflected form. These changes are not arbitrary; they follow specific patterns determined by the historical development of the Finnish language.

For example, in the strong alternation, the vowel 'i' might change to 'e' or 'ä'. In the weak alternation, vowels like 'o', 'ö', 'a', or 'ä' might lengthen or change quality. The specific vowel that alternates and the resulting vowel depend on the preceding and following sounds, as well as the type of suffix being added. Understanding äänenvaihtelu is essential for learners of Finnish as it affects the correct declension and conjugation of many words. It is a key characteristic that distinguishes Finnish from many other European languages.