doing 作定語，doing可能是形容詞，可能是動名詞，可能是現在分詞。無論是形容詞作定語，還是動名詞作定語，還是現在分詞作定語，都是修飾名詞。
例句：
1.This is an interesting book.
interesting是形容詞，修飾名詞book.
2.This is a swimming pool.
swimming是動名詞，修飾名詞pool.
3.The sleeping boy is Tom's brother.
sleeping是現在分詞，修飾名詞boy.
doing狀語，一定是現在分詞，現在分詞作狀語，修飾的是動詞或者句子。表示：時間、條件、結果、方式、原因、讓步、伴隨等。例句：
1.Walking in the street, I saw many people in the park.
2.Being ill, Mary was absent from school.
3.Alice was waiting for the bus at the station, reading the newspaper.
……
doing 作定語，doing可能是形容詞，可能是動名詞，可能是現在分詞。無論是形容詞作定語，還是動名詞作定語，還是現在分詞作定語，都是修飾名詞。
例句：
1.This is an interesting book.
interesting是形容詞，修飾名詞book.
2.This is a swimming pool.
swimming是動名詞，修飾名詞pool.
3.The sleeping boy is Tom's brother.
sleeping是現在分詞，修飾名詞boy.
doing狀語，一定是現在分詞，現在分詞作狀語，修飾的是動詞或者句子。表示：時間、條件、結果、方式、原因、讓步、伴隨等。例句：
1.Walking in the street, I saw many people in the park.
2.Being ill, Mary was absent from school.
3.Alice was waiting for the bus at the station, reading the newspaper.
……