You know Suse. -> Do yoy know Suse?Your friends visit you often.-> Do your friends visit you often?Andrew works in a restaurant.-> Does Andrew work in a restaurant?Does 뒤에 동사원형 쓰지 않는 것이 핵심 !!3강의 핵심은 바로 저 부분인것같아요 ~ 감사합니다 :)