동대문구를

In a sentence

• 동대문구를 방문해서 맛있는 음식을 먹었습니다.

  I visited Dongdaemun-gu and ate delicious food.

  In this sentence, '동대문구를' refers to the district 'Dongdaemun-gu', and the object marker '를' indicates that the district is the direct object of the verb '방문하다' ('to visit').

• 제가 동대문구를 자주 산책합니다.

  I often take walks in Dongdaemun-gu.

  Here, '동대문구를' again represents 'Dongdaemun-gu', the district receiving the action of the verb '산책하다' ('to take a walk').

• 동대문구를 잘 아는 친구와 함께 갔습니다.

  I went there with a friend who knows Dongdaemun-gu well.

  In this sentence, '동대문구를' serves as the object of the verb '알다' ('to know'), as utilized by '아는', describing the friend's association with the district.