1、a friend to everybody is a friend to nobody。

广交友，无深交。

2、Admonish your friends in private, praise them in public.

在私底下要忠告你的朋友，在公开场合又表扬你的朋友。

3、Admonish your friends in private, praise them in public. 

在私底下要忠告你的朋友，在公开场合又表扬你的朋友。

4、a friend is not so soon gotten as lost。

交友慢，失友快。

 5、A friend is best found in adversity. 

患难见真友。
 
6、 A brother may not be a friend, but a friend will always be a brother.
 
兄弟未必是朋友，而朋友总是兄弟。
 
7、 Between friends all is common.
 
朋友之间不分彼此。

8、Old friends and old wine are best.

陈酒味醇, 老友情深。

9、The friendship of a gentleman is insipid as water。

君子之交淡如水。

10、 A friend is a second self. 

朋友是另一个我。