thank you 与 be thankful有何不同？

thank you 与 be thankful有何不同？

thankful感激的;欣慰的[(+for)][+to-v][+that]
　　I was thankful for her help.
　　thankful的用法是be thankful for sb.to do sth
　　thank you 谢谢你。
　　Thank you for everything.
　　感谢你做的一切。