I'm 'grateful' (to you) for this opportunity. = I'm 'grateful' to have this opportunity. = I'm 'grateful' that I have this opportunity.
expressing my 'gratefulness' [=(more commonly) 'gratitude'] for this opportunity
The college 'gratefully' [='thankfully'] acknowledges your donation.
(..) And I thought, wow, he's gonna go primal , you know what I'm saying? If you find a mate in life, you should be loyal . In your case, it's grateful . Get away from me. Well , I think mate in life is stupid. I mean everybody just sit around. . . Mandy? Look at that. He's okay. She's gone. (..)2002 Ice Age