1. ashamed 意为“感到羞耻的”。如：
I’m ashamed of his behaviour. 我为他的表现感到羞耻。
It’s nothing to be ashamed of. 这没有什么可耻之处。
He was not ashamed of his lowly origin. 他对他出身低贱并不感到可耻。
After all, I’ve nothing to be ashamed of. 说到底我并没有值得羞愧之处。
You should be ashamed of doing that. 你应该为自己做那样的事感到羞耻。
I must admit to feeling ashamed of my conduct. 我必须承认我为我的行为感到羞耻。
2. shameful 意为“可耻的”、“丢脸的”。如：
It was a shameful act. 这是可耻的行为。
She’s quite shameful about wearing such sexy clothes. 她真是不知羞耻，穿那样的性感衣服。
It was shameful of them to surrender. =It was shameful that they surrendered. 他们的投降是可耻的。