He told the story charmingly, and all the children were captivated.

charmingly 是形容词 charming（迷人的）加上副词后缀 -ly 构成的副词形式，表示"以迷人的方式"或"迷人地"。charming 来自动词 charm（使着迷、吸引），加上 -ing 变成形容词。