This is every possible Scrabble word (the longest are filter and trifle):
ef
eft
el
elf
er
erg
et
fe
felt
fer
fet
fie
fig
fil
file
filer
filet
filter
fir
fire
fit
flier
flir
flirt
flit
flite
fret
frig
frit
gel
gelt
get
gie
gift
gilt
girl
girt
git
gite
grief
grift
grit
if
ire
it
left
leg
legit
lei
let
li
lie
lief
lier
life
lifer
lift
lifter
liger
lire
lit
lite
liter
litre
re
ref
refit
reft
reg
regilt
rei
reif
relit
ret
riel
rif
rife
rifle
rift
rig
rile
rite
teg
tel
ti
tie
tier
tiger
til
tile
tiler
tire
tirl
tref
trifle
trig
Those letters spell natural.
The letters in "these letters" can spell the phrase "ether settles." The letters can spell shorter words such as trestles, sheerest, shelters, and treeless.
Those letters will spell strum.
Those letters will spell exciting.
Those letters will spell stigma.
Those letters spell arrest.
Those letters spell exchange.
Those letters spell vulnerable.
Those letters spell illness.
Those letters spell holiday.
Those letters spell opposite.
Those letters spell campaign.