Check words you know to measure your vocabulary size (number of word families).
edge
stone
decide
much
melt
dawn
mount
pension
media
alternative
presence
negotiate
venue
cholesterol
thou
judicial
dependency
revolt
lad
aviation
aerobics
incarnate
sag
shear
rustic
ecumenical
psalm
oblivious
clandestine
inversion
monotony
radiology
permissive
conservancy
acne
octopus
bulkhead
parson
koran
mackerel
stampede
facile
dossier
shush
overkill
hotbed
wham
mollify
imbibe
cassava
midshipman
fixative
penury
aseptic
perforce
sumo
carotene
gardenia
rockabilly
expository
barbel
ficus
nutcase
theophylline
curie
toluene
chanteuse
mesenchymal
spinney
gamelan
blockhouse
cerebella
epidermoid
lacewing
amytal
appel
wolfram
chocoholic
oast
lamellar
vivendi
oubliette
percale
loquat
banneret
biogenetic
phenyl
euonymus
disbud
pestiferous
agri
chiffonade
cetane
amboyna
maestri
nizam
hydrolyte
shrove
bilboa
avoirdupois