如:am,is-was, are-were, do-did, see-saw, say-said, give-gave, get-got, go-went, come-came, have-had, eat-ate, take-took, run-ran, sing-sang, put-put, make-made, read-read, write-wrote, draw-drew, drink-drank, fly-flew, ride-rode, speak-spoke, sweep-swept, swim-swam, sit-sa