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.
(..) Look, l appreciate your concern, old-timer. But we have a kid waiting for us. Now, we're leaving. lf you'd help us, one toy to another, l'd sure be grateful. . . . . . (..)2010 Toy Story 3
(..) Come on, come on. Get in position. Wait! l can't find my other eye. -All right, whose foot's in my face? -lt's mine. Give it back. You have saved our lives. We are eternally grateful. Buzz! Mind if l squeeze in next to ya? Yes. No. l mean, why would l mind squeezing next to you? ls it hot in here? (..)2010 Toy Story 3