(adj.) thankful (unthankful); (n.) thankfulness
thank作为及物动词，常用搭配是thank sb (for sth / for doing sth)，如：
She said goodbye and thanked us for coming.
正：Thank you for your help.
误：Thank your help.
1. have sb to thank for (doing) sth 归功于，如：
I have my parents to thank for my success.
2. thank your lucky stars 感谢你的幸运之星，口语中用于表达幸运，尤其是躲过了不愉快或危险的事。如：
Just thank your lucky stars you weren't in the house at the time.
(adj.) appreciative (inappreciative); (n.) appreciation
appreciate作为“感激”解释时是及物动词，常用搭配：appreciate doing sth，后跟动名词或代词it代指的事情。习惯上只能接“事”作宾语(object)，而不能接“人”作宾语：
正：I'd appreciate some help.
误：I'd appreciate you for some help.
In time you'll appreciate the beauty and subtlety of this language.
We greatly appreciate your getting the goods to us at such short notice.
在这句里，“We greatly appreciate...”和“Thank you for...”含意相同。
I fully appreciate your concern. We will do all in our power to help.
Their investments have appreciated over the years.
（反）ungrateful; (n.) gratitude (ingratitude)
grateful没有相应的动词，它的常用搭配是be grateful to sb for sth，或者后面跟不定式或that从句，如：
I am extremely grateful to all the teachers for their help.
She seems to think I should be grateful to have a job at all.
He was grateful that she didn't tell his parents about the incident.
I would be grateful if you could send the completed form back as soon as possible.
"When you are 'grateful' to someone, you can sometimes feel a little 'beholden' to them. It creates a feeling of 'owingness'." 也就是说grateful带有一点“义务”的性质。
而另一方面，"When we appreciate someone or something there is a feeling of ending. There is a feeling of finality. We do not feel the need to pay this person back." 当我们用appreciate有点意味着这件事的结束，不需要再做什么回报。
另外，oblige (vt.) 一词也有“使感激”的意思，如：
I'm much obliged to you. 我非常感谢你。
Parents are obliged by law to send their children to school.