은 (eun) and 는 (neun): There are at least two applications for 은 (eun) and 는 (neun): contrast and topic marker. In short, contrast defines the sentence style (Question or answer) and topic marker defines the subject in a sentence. Just like before; if there is a final consonant, use 은, if not, use 는. In practice – contrast: The question uses 이/가 and the answer 은/는. 수나가 학교에 갑니까? (sunaga haggyoleul gabnikka) – Is Suna going to school? 수나는 학교에 갑니다. (sunaneun haggyoleul gabnida) – Suna is going to School. In practice – topic marker: Noun’s with a 은 (eun) and 는 (neun) in the end become the topic of the sentence. With every sentence about a persons action, use 은 (eun) and 는 (neun). Otherwise use 이/가 . http://www.weeklykorean.com