grateful&thankful

grateful和thankful同为adj.
为什么grateful的用法是be grateful to sb. for doing sth.
而thankful的用法是be thankful for sb.to do sth.

为什么呀？？？

grateful&thankful grateful for的具体用法 l ining on a grateful world什么意思 The dog is grateful __________you. A,to B,for when we meet the right one, we will know how to be grateful. The poor children are really grateful _____ Project Hope's help. You were very grateful.这句话是对的吗?属于常用句吗? im most grateful to you for the help you ____me when i was in trouble Politicians rarely need an excuse to shower grateful constituents with other people's money 翻译？ 帮我翻译一句,商务的: grateful for a CIFC5% price on the following two items