There are four main purposes for ending a sentence with ~고요
1. The sentence isn’t yet finished.
e.g 저는 빵을 좋아하고요…달끼 잼도 좋아해요.
(Note: when providing additional information you should attach 도 to nouns.)
2. Additional explanations.
e.g 저는 밥을 좋아해요. 왜냐하면 ~~ 맛있어 가지고요
3. Using can make a sentence sound softer (in spoken Korean) 저는 학생이고요 can give a softer feeling to the listener than saying 저는 학생입니다.
4. Questions
e.g 개를 좋하해요? 고양이가 아니고요?
Sutdy-Korean 