thankful to后面加人，表示感谢某人，例句：I am very thankful to my teachers.而thankful for后面加事，表示对某事表示感谢。例句：I am thankful for them giving birth to me.
thankful解释及例句
adj.感激的；感激；感谢；欣慰
I could see him standing there with a thankful smile.
我能看到他站在那里，带着感激的微笑。
When you're thankful, you feel it's your duty to show love to others.
当你心存感激的时候，你觉得向别人表达爱是你的责任。
I was thankful to see they'd all arrived safely.
看到他们都平安到达，我感到欣慰。
He wasn't badly hurt ─ that's something to be thankful for.
他的伤不重，这倒是值得庆幸。
I was thankful that he hadn't been hurt.
他没有受伤，我感到很欣慰。