'work in pairs' means work with your partner, right? And if you translate this to Korean, it is 짝지어 일하다. work is 일하다 and pair is 짝 in Korean

it depends on contexts, but if it is regarding persons or co-workers at a workplace. it could mean, '두 사람씩(이) 짝을지어' 일하다.or '두 사람씩(이) 한조가 되어' 일하다. in here, '한조' means 'a group'. here is another example, we worked in pairs for the role-play exercise. 우리는 (두 사람이) 한조가 되어 역활극 연습을 했다.