BE
WAS / WERE
HELP
HELPED
USE
USED
MAKE
MADE
ASSEMBLE
ASSEMBLED
STUDY
STUDIED
ENROL
ENROLLED
INFEST
INFESTED
LIE
LAY
CONTAMINATE
CONTAMINATED
REDUCE
REDUCED
MOVE
MOVED
WEAR
WORE
INVENT
INVENTED
MARRY
MARRIED
ARRIVE
ARRIVE
ASK
ASKED
RECEIVE
RECEIVED
SAIL
SAILED
BE BORN
WAS BORN
PERFORM
PERFORMED
SHOW
SHOWED
IMPROVE
IMPROVED
WRITE
WROTE
TRAVEL
TRAVELLED
TREAT
TREATED
ESTABLISH
ESTABLISHED
RETURN
RETURNED