Adnominal ending form(관형사형어미) for a verb has four kinds of tense * present -는 저기 가는 자동차 * past (으)ㄴ 어제 먹은 빵 * incomplete past -던 어제 먹던 빵 * future -(으)ㄹ 내일 먹을 밥 present : 녹슬다 + 는 => 녹스는 past : 녹슬다 + (으)ㄴ => 녹슨 (녹슬은 is wrong form of 녹슨) future : 녹슬다 + -(으)ㄹ=> 녹슬 incomplete past: 녹슬다+더=>녹슬던

녹슨=녹슬은 녹스는 : 녹이 날 수 있는 녹슨 : I found a rusted knife. 녹스는 = 녹이 날 수 있는 : Keep the knife dry. The knife is a rust-easy stuff. I should check up the word 'rust-easy'. But I you it in this meaing. It is easy to be rusted. If you know the correct expression, please let me know.

녹슨=녹슬은 녹스는 : 녹이 날 수 있는 녹슨 : I found a rusting knife. The knife has rusted. 녹스는 = 녹이 날 수 있는 : Keep the knife dry. The knife is a rust-easy stuff. It does not yet rust but it will rust. If you know the correct expression, please let me know.