어 쓰다

use it sparingly, in turns, together

A manner verb joined to 쓰다 'use' says how the using is done: 아껴 쓰다 is using sparingly ('물을 아껴씁시다!'), 돌려 쓰다 is rotating through a set — 이 다섯 가지를 돌려 쓸 수가 있어요 — and 나누어 쓰다 is sharing: 병실을 두 분이랑 같이 나누어 썼는데. 쓰다 also means wearing on the head, which is what 모자 고쳐 쓰는 is doing. Be warned that three lines here (해써, 빵밀어써여, 잃어써) are only baby-talk spellings of ordinary past tenses that happen to look the same.