不规则
am/is=was
are=were
do/does=did
have/has=had
fly=flew
eat=ate
draw=drew
make=made
go=went
sing=sang
take=took
come=came
write=wrote
see=saw
sit=sat
give=gave
buy=bought
begin=began
run=ran
drink=drank
不规则
am/is=was
are=were
do/does=did
have/has=had
fly=flew
eat=ate
draw=drew
make=made
go=went
sing=sang
take=took
come=came
write=wrote
see=saw
sit=sat
give=gave
buy=bought
begin=began
run=ran
drink=drank