The first '-는/-ㄴ' is a conjugation form of verbs or adjectives to modify nouns, and the second one is a marker which makes a noun into a subject, technically a topic. e.g. 좋아하다(to like) ☞좋아하는 배우(an actor who I like) 가르치다(to teach) ☞ 가르치는 사람(people who teach) = 선생님(teachers) 배우다(to learn) ☞ 배우는 + noun 먹다(to eat) ☞ 먹는 + noun 사과+는 맛있어요(= Apples are delicious) "사과" can be a subject or object depending on markers. With the subject markers 이/가/는/은, it can be a subject.On the other hand, it also can be an object with the object markers 을/를 like "사과+를 먹었어요(I ate an apple)". \^o^/