The following verbs vary between ed and t (d) in the past tense and the past participle. In some of them, this variation is a mere difference of spelling. In writing, the ed forms are preferred in most cases; in speaking, the t forms are very common.
bless | blessed, blest |
burn | burned, burnt |
curse | cursed, curst |
dare | dared (less commonly, durst) |
dream | dreamed, dreamt |
dress | dressed, drest |
gird | girded, girt |
kneel | kneeled, knelt |
knit | knit, knitted |
learn | learned, learnt |
pen (shut up) | penned, pent |
quit | quitted, quit |
shred | shredded, shred |
smell | smelled, smelt |
speed | sped, speeded |
spell | spelled, spelt |
spill | spilled, spilt |
spoil | spoiled, spoilt |
stay | stayed, staid |
sweat | sweated, sweat |
wed | wedded |