Home Conversations Behaviour I don’t know (Ewan Ko) ConversationsBehaviourCustomsBody LanguageGeneral CustomsPhilippinesPosture I don’t know (Ewan Ko) By Marco de Groen - Mar 5, 2014 SHARE Facebook Twitter Yes is signified by a nod or raising of the eyebrows. No is signified by shaking the head. Jerking the head down and raising the shoulders means “I don’t know” or “ewan ko”