Finnish vowel harmony

Finnish vowels are categorized as back (a,o,u), front (ä,ö,y), or indifferent (i,e).

The vowels in a simple word are either back and/or indifferent, or front and/or indifferent. The vowels in a compound word, which is a word that contains more than one simple word, can be a combination of back and front vowels; the vowel-harmony rule applies to simple words rather than compound words as a whole.

a

o

u

i

e

ä

ö

y