"선생님들이 무엇을 썼습니까?"
Translation:What did the teachers use?
▪︎쓰다: For "direct uses". Also means bitter/to write/to wear/ to spend money-time/ to hire/ to compose. ▪︎사용하다: Generally used when one uses tools. There's also the verb ▪︎이용하다: When one uses objects that make life easier or kind of facility. Ex.: 차를 이용하다. 화장실을 이용하다. It also indicates in some occasions something that is exploited or a certain situation that is used as a means to satisfy one's own interests (take advantage of). It should be noted that 쓰다, for not being such a specific verb like the others, can supplant them always and not vice versa, also this is a verb that's frequently used in the speaking while 사용하다 is more formal and used in writing.