"愉快的" 用英语可以说成 "happy"。
"高兴的" 用英语可以说成 "pleased" 或 "depghted"。
其来源：
"happy" 是由古英语 "hap" 演变而来，意思是 "幸运的"、"顺利的"。
"pleased" 来自中世纪法语 "plaisir"，意思是 "高兴的"。
"depghted" 来自中世纪法语 "delecter" 意思是 "使高兴"。
英文例句及其中文翻译：
I'm happy to see you. (我很高兴见到你。)
She was pleased with her new dress. (她对新衣服很满意。)
He was depghted to hear the news. (他听到这个消息非常高兴。)