을 (eul) and 를 (reul) are the last postposition we’ll cover. As said before, postpositions change the noun into the subject of the verb.
신문을 봅니다 – I read a newspaper.
커피를 마십니다 – I drink a cup of coffee.
수영을 합니다 – I swim
지우개를 삽니다 – I buy an eraser.