He told the terrible accident brokenly, pausing frequently.

brokenly 是形容词 broken（破碎的）加上副词后缀 -ly 构成的副词。broken 本意是"破碎的"，引申为"不连贯的"。brokenly 表示"断断续续地"，形容说话时因情绪激动等原因导致语句不连贯、时常停顿的状态。