사용이 · 사용을
use, usage
Example
도서관에서는 휴대폰 사용을 자제해 주세요.
Please refrain from using your phone in the library.
Word parts
사 employ+용 use
Literally 'employ and use'.
Good to know
사용 is for tools and things; 이용 is for services and facilities like the subway.
Related words