Check words you know to measure your vocabulary size (number of word families).
interest
let
million
roll
beer
fault
recommend
dollar
extract
summary
founded
assign
sheriff
delicate
nonetheless
frontier
facial
diagnostic
comrade
millilitre
oscillate
humanities
audition
glacier
hilarious
hefty
decompose
char
mandarin
purr
oblivion
vista
scald
legible
ewe
wicket
capricious
desecrate
litigant
dejected
autonomic
pox
azalea
methanol
barium
depredation
interpose
skittish
refectory
firmament
unhinged
chaff
prion
footloose
neurobiology
tamp
forswear
overawe
soothsayer
browbeat
clade
coopt
chine
cabriolet
neurophysiology
shipwright
cottar
gimp
cyclad
rondo
irruption
phat
generis
extrasolar
multicoloured
garbanzo
episiotomy
tallboy
centrale
arabica
spareribs
asterism
candlewick
synchro
phenyl
punctilio
macrophyte
encephalomyelitis
hazan
guayabera
condign
sorel
faugh
oxalis
kalmia
arenite
mordent
arytenoid
jurat
cairene