一叶知秋 英文翻译

直译：you can know the awtumn's coming through a follen leaf
意译：you can know the whole according to a detail

you see a leaf fall and you think you know where the wind blows

The colour of a leave tells the season.
The colour of trees tells the season.

autumn comes with falling leaves

the falling of one leaf heralds the autumn.
OR
it is a straw in the wind.
OR
a small sign can indicate a great trend.

Autumn comes with the falling leaves。