These are thrown on largely for effect. They may also denote the relationship between the child's father and the person for whom the child is named. They are not considered names properly so called. So much so that it is dismissed as 'no name' should one introduce one's self with only the prefix.
example a girl born on Saturday and named after her father''s mother will be called Maame Ama.
Egya [pronounced Eja'] father
example Boy born on Friday might be called Nana Kofi.
Note: When the prefixes Owura and Egya are used with Kweku, the day name is abbreviated resulting in Egyeeku and Owureku