사병이 · 사병을
enlisted soldier, private
Example
대부분의 사병은 이 년이 안 되게 복무해요.
Most enlisted soldiers serve for less than two years.
Word parts
사 soldier+병 troops
Literally 'soldier' + 'troops' — the rank and file, not officers.
Good to know
사병 contrasts with 장교; for soldiers in general, 군인 is the everyday word.