6 letter words:
foists9,
tifoso9,
5 letter words:
fists8,
foist8,
foots8,
sifts8,
softs8,
soots5,
4 letter words:
fist7,
fits7,
foot7,
foss7,
oofs7,
sift7,
soft7,
isos4,
oots4,
sist4,
sits4,
soot4,
sots4,
toss4,
3 letter words:
fit6,
ifs6,
oft6,
oof6,
sif6,
ios3,
iso3,
its3,
oos3,
oot3,
sis3,
sit3,
sos3,
sot3,
tis3,
too3,
2 letter words:
if5,
of5,
io2,
is2,
it2,
oi2,
oo2,
os2,
si2,
so2,
st2,
ti2,
to2,