Henry founded a school (for sailors) to which he invited everyone (who could help him).
可以改写成 henry founded a sailors' school which he invited everyone(who could help him) to
中文:哼利成立了一所海事学院,在这所海事学院里,他可以邀请所有对他有帮助的人到这个学院里!
for 的意思是:给(给水手的学习的学校) which 定语从句中的关系代词 意思是:指代这所学校 .同理 WHO 指代everyone