Spell the root plus the suffix (e-drop)
infinite + y
infinity
permit +ed
permitted
confuse +ion
confusion
silly +est
silliest
infinite +ly
infinitely
derive + ation
derivation
star +y
starry
intense +ity
intensity
category +s
categories
astronomic +al
astronomical
continue +al
continual
water +y
watery
implicate +ed
implicated
busy +ness
business
glorify +ing
glorifying
recharge + able
rechargeable
marvel +ous
marvelous
probable +y
probably
convey +or
conveyor
infinite +y
infinity
dance +able
danceable
propel +er
propeller
recite + s
recites
bully +ing
bullying
lobby +ist
lobbyist