affermare bedeutet auf Englisch

claim [claimed, claiming, claims]▼(to state a new fact)
verb
[UK: kleɪm] [US: ˈkleɪm]John claims that he's rich. = John afferma di essere ricco.

opine [opined, opining, opines]▼(to state as an opinion)
verb
[UK: ə.ˈpaɪn] [US: oˈpaɪn]