firmare betyder på engelska

ink [inked, inking, inks]▼(sign a document)
verb
[UK: ɪŋk] [US: ˈɪŋk]

sign [signed, signing, signs]▼(to make (a document) official by writing one's signature)
verb
[UK: saɪn] [US: ˈsaɪn]Where do I sign? = Dove firmo?

cosign [cosigned, cosigning, cosigns]▼(to sign a document jointly with another person)
verb
[UK: kˈɒsaɪn] [US: kˈɑːsaɪn]

countersign [countersigned, countersigning, countersigns]▼(add a second signature)
verb
[UK: ˈkaʊn.tə.saɪn] [US: ˈkaʊn.tə.saɪn]