appreciation [appreciations](a just valuation or estimate of merit, worth, weight, etc.; recognition of excellence) noun [UK: ə.ˌpriːʃ.i.ˈeɪʃ.n̩] [US: ə.ˌpriːʃ.i.ˈeɪʃ.n̩]
gratefulness(the state of being grateful) noun [UK: ˈɡreɪt.fəl.nəs] [US: ˈɡreɪt.fəl.nəs]
gratitudinenoun {f}
gratitude(state of being grateful) noun [UK: ˈɡræ.tɪ.tjuːd] [US: ˈɡræ.tə.ˌtuːd]You have my eternal gratitude. = Ha la mia eterna gratitudine.