VOWEL HARMONY: There are 8 vowels in the Finnish alphabet. The vowels a, o, u can never occur together with ä, ö, y in a single word, unless it is a compound word. This is called vowel harmony. The vowels e and i can with any vowel. They are neutral vowels. It is important to keep your a’s and ä’s separate as the meaning as the meaning of the words or sentence can be different – sometimes very different.