A friend is easier lost than found得朋友难，失朋友易。
A friend in need is a friend indeed患难见真情。
When you are young, you know pines and cypresses； when you are in trouble, you see friendship岁寒知松柏；患难见交情。
The two of them are united, and their profits are cut off二人同心，其利断金。
A thousand friends are few, but one enemy is too many朋友千人尚觉少，仇敌一人犹嫌多。
To prepare a friend, three things are required: to honor him present, praise him absent, and assist him in his necessities维护朋友，有三件事情要做到：当面要尊重他，不在场时要表扬他，苦难时要帮助他。
Between friends all is common朋友之间不分彼此。
Friendship is almost always the union of a part of one mind with a part of another； people are friends in spots友谊是两者思想的结合，志趣相投才能成为朋友。
It is well that there is no one without a fault, for he would not have a friend in the world世界上没有不犯错误的人。想交没有错误的朋友，你就没有朋友。
Better an open enemy than a false friend明枪易躲，暗箭难防。
The more we love our friends, the less we flatter them对朋友爱得越深，奉承得就越少。
A life without a friend is a life without a sun人生没有朋友，犹如生活没有了太阳。
A man who has friends must show himself friendly要有朋友，必须以友谊待人。
No road is long with good company与良友为伴，路遥不觉远。
Be slow in choosing a friend； slower in changing选择朋友要审慎，摒弃更要审又慎。
Birds of a feather flock together物以类聚，人以群分。
A man is known by his friends什么人交什么朋友。
Keep good men company and you shall be of the number近朱者赤，近墨者黑。
A friend to all is a friend to none滥交者无友。
A brother may not be a friend, but a friend will always be a brother兄弟可能不是朋友，但朋友永远是兄弟。
这些谚语以简洁的方式表达了友谊的珍贵、选择和维系友谊的重要性以及朋友之间的互相帮助和支持。希望这些谚语能够帮助你更好地理解和表达与朋友之间的关系。