은 재미있다

is fun; is interesting

→ 은
phrase Rare #16,049
is fun; is interesting 은 is a topic marker attached to a noun or noun phrase. 재미있다 can mean “to be fun” or “to be interesting,” depending on context. The form 은 is used after a noun ending in a consonant; after a vowel, 는 is used instead.
KO: 여행은 재미있다.
EN: Traveling is fun.

여행은 재미있다.

Traveling is fun.

은 재미있다.

Dancing is fun.

언어를 배우는 은 재미있다.

Learning a language is fun.