Sigfastsson
nafnorð karlkyn Föðurnafn
Fallbeygingar
Eintala
nefnifall
Sigfastsson
þolfall
Sigfastsson
þágufall
Sigfastssyni
eignarfall
Sigfastssonar
Fleirtala
nefnifall
Sigfastssynir
þolfall
Sigfastssyni
þágufall
Sigfastssonum
eignarfall
Sigfastssona