base vs. past simple vs. past participle
go
gone
bring
brought
begin
begun
buy
bought
run
be
been
have
had
sing
sung
put
put
do
done
see
seen
hear
heard
drink
drunk
find
found
read
read
eat
eaten
feel
felt
ring
rung
think
thought
teach
taught
wear
worn
keep
kept
swim
swum
stand
stood
become