どこ means “where.” It is used to ask about location. You can use it with particles like に, で, and へ depending on the meaning. Key points: • どこに = where (location/existence) • どこで = where (action place) • どこへ = where (destination) • Common in daily questions Example: “トイレはどこですか” means “Where is the toilet?” “どこで勉強しますか” means “Where do you study?” Use に with existence or location, で with actions, and へ with destinations. This is a great way to practice particles too. Practice by asking about places: どこに住んでいますか, どこで働きますか.