이걸 쓴

that used this

→ 이것+을

phrase Uncommon #12,798

that used this 이걸 means “this” as the object of the verb. 쓴 is the past attributive form of 쓰다, which can mean “use,” “write,” or “wear,” depending on context. This phrase usually modifies a noun.

KO: 내가 이걸 쓴 이유는 간단해요.

EN: The reason I used this is simple.