The Object Marker, and Passing Through (を)

を is the most ordinary job this particle does, marking whatever noun the verb is directly doing something to. It shows up constantly paired with a noun+する verb too, 発表をします (to give a presentation), 予約をします (to make a reservation), the noun takes を before する turns it into an action.

None of these verbs, 行く, 曲がる, 登る, are being done “to” the road or the corner the way 書く is done to a kanji. を here marks the space the movement happens through, not a target being acted on. English keeps this distinction with different prepositions, “along,” “at,” “up”, Japanese uses the same particle for all of it.