This is the academic word list, can be used to study for IELTS test. Pretty systematic and simple to learn.

1. accommodate
accommodated
accommodates
accommodating
accommodation
analogy
analogies
analogous
anticipate
anticipated
anticipates
anticipating
anticipation
unanticipated
assure
assurances
assured
assuredly
assures
assunng
attain
attainable
attained
attaining
attainment
attainments
attains
unattainable
behalf
bulk
bulky
cease
ceased
ceaseless
ceases
ceasing
coherent
coherence
coherently
incoherent
coincides
coinciding
coincidence
coincidences
coincident
coincidental
commence
commenced
commences
commencement
commencing
recommences
recommenced
recommencing
compatible
compatibility
incompatibility
incompatible
concurrent
concurrently
confine
confined
confines
confining
unconfined
controversy
controversies
controversial
controversially
uncontroversial
converse
conversely
device
devices
devote
devoted
devotedly
devotes
devoting
devotion
devotions
incoherentlY-- ..~ .•••.•.~diminish
/ ,
coincide
coincided
d
iminished
diminishes
diminishing
diminution
undiminished
distort
distorted
distorting
distortion
distortions
distorts
duration
erode
eroded
erodes
eroding
erosion
ethic
ethical
ethically
ethics
unethical
format
formatted
formatting
formats
found
founded
founder
founders
founding
unfounded
.inherent
inherently
insight
insightful
insights
integral
intermediate
manual
manually
manuals
mature
immature
immaturity
maturation

2. maturational
matured
matures
maturing
maturity
mediate
mediated
mediates
mediating
mediation
medium
military
minimal
mininialisation
minimalise
minimalises
minimalised
minimalising
minimalist
minimalists
minimalistic
minimalization
minimalize
minimalized
minimalizes
minimalizing
minimally
mutual
mutually
norm
norms
overlap
overlapped
overlapping
overlaps
oassive
passively
passivity
oortion
portions
preliminary
preliminaries
Drotocol
protocols
qualitative
qualitatively
/'
refine
refined
refinement
refinements
refines
refining
relax
relaxation
relaxed
relaxes
relaxing
restrain ('rr,,, -,
restrained
restraining
restrains
restraint
restraints
unrestrained
revolution
revolutionary
revolutionaries
revolutionise
revolutionised
revolutionises
revolutionising
revolutionist
revolutionists
revolutionize
revolutionized
revolutionizes
revolutionizing
revolutions
rigid
rigidities
rigidity
rigidly
route
routed
routes
routing
scenario
scenarios
sphere
spheres
spherical
spherically
subordinate
subordinates
subordination
supplement
supplementary
supplemented
supplementing
supplements
suspend
suspended
suspending
suspends
suspenSIOn
team
teamed
teaming
teams
temporary
temporarily
trigger
triggered
triggering
triggers
unify
unification
unified
unifies
unifying
violate
violated
violates
violating
violation
violations
vision