Check words you know to measure your vocabulary size (number of word families).
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inform
bag
truck
twin
citizen
compare
outcome
civilise
collapse
yield
erupt
impair
cling
privatise
botany
bulletin
jockey
tabloid
syndicate
bustle
mesh
encode
null
prick
majestic
vehement
inversion
rudder
biographer
adhesive
reverie
pallet
resection
surreptitious
hiatus
maul
kosher
somersault
lieu
livid
dollop
commandeer
hovel
jacuzzi
candelabra
ineptitude
unhinged
gastritis
bonsai
tambourine
magnetosphere
nectarine
summat
reprove
teepee
residuum
monolingual
spry
microtubule
parapsychology
sot
ablution
byre
provencal
coleus
contessa
moto
nuclease
effing
bounder
hydrophilic
pleurisy
deadbolt
gruyere
spokeshave
tisane
acyl
medigap
valine
concertacion
rubrum
chia
vibrio
femoris
sternocleidomastoid
hematocrit
digestif
microcellular
myxoedema
lorikeet
marengo
graduand
charpoy
isopod
helvetica
seraphin
felid
kabbala