路遥知马力，日久见人心。用英语怎么说啊

按字面可以翻译成As distance tests a horse's strength, so time reveals a person's heart.
比较意译的表达是Time tries all.
而比较地道的英文谚语是A man knows his companion in a long journey and a little inn.

路遥知马力，日久见人心。
As distance tests a horse’s strength．so time reveals a person's heart
As a long journey tests a horse's strength,so a long acquaintance shows a man's heart．

属类：【习语名句】-〖俗语〗

Before you make a friend, eat a bushel of salt with him.

Time tries all.