[mike@thiscomputer ~]$ grep ^too /usr/share/dict/words 
too
took
tool
tooled
tooler
toolers
tooling
tools
tooth
toothbrush
toothbrushes
toothpaste
toothpick
toothpicks
[mike@thiscomputer ~]$ grep ^tu /usr/share/dict/words 
tub
tube
tuber
tuberculosis
tubers
tubes
tubing
tubs
tuck
tucked
tucking
tucks
tuft
tufts
tug
tugs
tuition
tulip
tulips
tumble
tumbled
tumbler
tumblers
tumbles
tumbling
tumor
tumors
tumult
tumults
tumultuous
tunable
tune
tuned
tuner
tuners
tunes
tunic
tunics
tuning
tunnel
tunneled
tunnels
tuple
tuples
turban
turbans
turbulence
turbulent
turbulently
turf
turgid
turgidly
turkey
turkeys
turmoil
turmoils
turn
turnable
turnaround
turned
turner
turners
turning
turnings
turnip
turnips
turnover
turns
turpentine
turquoise
turret
turrets
turtle
turtleneck
turtles
tutor
tutored
tutorial
tutorials
tutoring
tutors