Everyone knows that. Each trainer has a signature Pokemon that they strongly associate with, meaning they are represented by that type.
Rufina Laminton and Ethelia, ghost type
Harun Demir and Serhat, ground type
Hellina Rozanov and Sanya, assorted
Charles and Getrud Laminton and Macrus, ghost and psychic types
Joshien Fontaine and Sophia, normal type
Florence Fontaine and Gavona, dark type