5 letter words:
fesse8,
fosse8,
seifs8,
issei5,
seise5,
4 letter words:
fees7,
fess7,
foes7,
foss7,
seif7,
eses4,
oses4,
sees4,
seis4,
3 letter words:
efs6,
fee6,
fes6,
fie6,
foe6,
ifs6,
ess3,
oes3,
ose3,
see3,
sei3,
sis3,
sos3,
2 letter words:
ef5,
fe5,
if5,
of5,
es2,
is2,
oe2,
oi2,
os2,
si2,
so2,