Karelian alphabet are from the ISO basic Latin alphabet, five are derived from basic Latin letters by the addition of diacritical marks, and the final character is the apostrophe, which signifies palatalization of the preceding sound. The entire range of sounds of native Karelian words is intended to be represented by this set of characters. This unified alphabet was approved in 2007 as a replacement for the separate Olonets Karelian and Karelian Proper alphabets. The letters Ä and Ö are vowels which, unlike the German umlauts, are considered to be distinct and are alphabetized separately from the corresponding vowels without the umlauts.
Alphabet abjads and abugidas. These three differ from each other in the way they treat vowels: abjads have letters for consonants and leave most vowels unexpressed; abugidas are also consonant-based, but indicate vowels with diacritics to or a systematic graphic modification of the consonants. In alphabets in the narrow sense, on the other hand, consonants and vowels are written as independent letters. The earliest known alphabet in the wider sense is the Wadi el-Hol script, believed to be an abjad, which through its successor Phoenician is the ancestor of modern alphabets, including Arabic, Greek, Latin (via the Old Italic alphabet), Cyrillic