3 sentences for 纷纷 (fēn​fēn — in profusion)

1. 秋风吹过，树上的黄叶纷纷凋落。

   qiū​fēng chuī guò, shù​shàng de huáng​yè fēn​fēn diāo luò.

   As the autumn wind blows, yellow leaves fall from the trees one after another.

   Source: Dong Chinese Dictionary

2. 秋天到了，树叶纷纷从树上落下。

   qiū​tiān dào le, shù​yè fēn​fēn cóng shù​shàng luò​xià.

   Autumn has arrived, and leaves are falling from the trees.

   Source: Dong Chinese Dictionary

3. 秋风吹过，枯叶纷纷从树上飘落下来。

   qiū​fēng chuī guò, kū​yè fēn​fēn cóng shù​shàng piāo​luò xià​lai.

   The autumn wind blows, and withered leaves fall from the trees one after another.

   Source: Dong Chinese Dictionary