A fo may grow gray, but never good.

a fox may grow gray, but never good.

江山易改，本性难移。

a friend in need is a friend indeed.

患难见真情。

a friend is easier lost than found.

得朋友难，失朋友易。

a friend is never known till a man has need.

需要之时方知友。

a friend without faults will never be found.

没有十全十美的朋友。

'after you' is good manners.

“您先请”是礼貌。

a good beginning is half done.

良好的开端是成功的一半。

a good beginning makes a good ending.

善始者善终。

a good book is a good friend.