if any和if ever在意义和用法上有什么区别?

if any:若有的话
Examples:
1.We'll let you know if any vacancies come up.
一有空缺我们就通知你.
2.If any oil gets on the car tyres,it will perish them.
汽车胎沾上油就会毁坏.
3.Please correct my mistakes if any(=if there is any mistake).如果有的话,请改正我的错误.
if ever:conj.如果有过的话(如果发生过的话)
Examples:
1.That was a fine meal if ever there was one!
那确实是一顿丰盛的饭.
2.She seldom,if ever,goes to the cinema.
她难得看电影.
3.The island is seldom,if ever,visited by ships.
这个岛难得有船停靠.(=if the island has ever been visited by ships)
4.He is a great musician if ever there was one.
如果曾经有过伟大的音乐家,那他就是一个.