Verbs differ in the manner of forming their past tenses, and participles, or adjectives. Those ending in ed are called regular; those which take any other termination are irregular. There are about two hundred of the latter in our language, which differ in various ways. Some of them have the past tense and the past participle the same; as,

BidBidBid
KnitKnitKnit
ShutShutShut
LetLetLet
SpreadSpreadSpread, etc.

Others have the past tense and participle alike, but different from the present; as,

LendLentLent
SendSentSent
BendBentBent
WendWentWent
BuildBuilt or buildedBuilt
ThinkThoughtThought, etc.

Some have the present and past tense and participle different; as,

BlowBlewBlown
GrowGrewGrown
BeginBeganBegun
SeeSawSeen
WriteWroteWritten
GiveGaveGiven
SpeakSpokeSpoken
RiseRoseRisen
FallFellFallen, etc.

There are a few which are made up of different radicals, which have been wedded together by habit, to avoid the frequent and unpleasant recurrence of the same word; as,

AmWasBeen
Go (wend)WentGone, etc.

Some which were formerly irregular, are now generally used with the regular termination, in either the past tense or participle, or both; as,

HangHung or hangedHung or hanged
DareDared or durstDared
ClotheClad or clothedClad or clothed
WorkWorked or wroughtWorked
ShineShined or shoneShone or shined
SpillSpilled or spiltSpilt or spilled, etc.