以下是一些關于友誼的英語諺語：

1.A friend in need is a friend indeed.

2.Friends are like wine; the older, the better.

3.True friendship lasts forever.

4.Friendship is a plant that needs constant watering.

5.Friendship cannot stand always on one side.

6.Friends must part.

7.Friendship is love with understanding.

8.Friends are like books; you don't need many, but you need the good ones.

9.A friend to all is a friend to none.

10.Friends are born, not made.

11.A man is known by the company he keeps.

12.The only way to have a friend is to be a friend.

13.A friend without faults will never be found.

14.Two are better than one; because they have a good return for their labour.

15.No man is a island, entire of itself; every man is a piece of the continent, a part of the main.

這些諺語強調了友誼的重要性、真摯性、持久性和相互性。它們提醒我們，友誼需要不斷的維護和投入，同時也告訴我們，真正的友誼是能夠經受住時間考驗的。