# Python 3, 154 bytes

    M=input();Q={'ser':'er','ver':'veI','ir':'ib'}.get(M);print([(Q if Q else M[:-2]+("ab"if M[-2:]=="ar"else"I"))+j for j in"a as a amos ais an".split(' ')])

<hr>

### Ungolfed

    M=input()
    Q={'ser':'er','ver':'veI','ir':'ib'}.get(M)

    H=[]
    for j in "a as a amos ais an".split(' '):
        if Q:
            F += Q
        else:
            if M[-2:] == "ar":
                F = M[:-2] + "ab"
            else:
                F = M[:-2] + "I"
        H += F + j

    print(H)