 The values of many of the letters are thought to have been displaced under Cyrillic influence or to have become confused through the early spread to different dialects so the original values are not always clear.For instance, the letter "yu" Ⱓ is thought to have perhaps originally had the sound /u/ but was displaced by the adoption of an "oѵ" ligature Ⱆ under the influence of later Cyrillic.Other letters were late creations after a Cyrillic model.