begin–beginning
beg-begging
dig-digging
dip-dipping
drop-dropping
forget-forgetting
get – getting
hit-hitting
mop-mopping
nod-nodding
pat-patting
put–putting
run-running
swim-swimming
sit–sitting
win-winning
regret-regretting
set-setting
stop-stopping
一共19个,差不多够用了吧.