规则动词的过去式变化如下：
（1）一般情况下,动词词尾加 ed ,
如： work—worked； play—played；want— wanted； act—acted
（2）以不发音的 e 结尾动词,动词词尾加 d,
如： live—lived； move—moved； decide—decided； decline—declined； hope—hoped；
（3）以辅音字母 + y结尾的动词,把y变为i 再加ed,
如： studied tried copied justified cried carried embodied emptied
（4）以一个辅音字母结尾的重读闭音节动词,双写词尾辅音字母,再加 ed,
如： stopped begged fretted dragged dropped planned dotted dripped
（5）注：不规则动词的过去式变化规律性不强,须多加记忆.
go - went,
make - made,
get - got ,
buy - bought ,
come - came ,
fly-flew ,
is/am-was,
are-were ,
see-saw ,
bring-brought,
do-did,
teach-taught,
think-thought,
say-said,
sit-sat.
read-read,
spend-spent,
eat-ate,
give-gave,
sit-sat,
tell-told,
write-wrote,
feel-felt,
find-found,
hear-heard,
know-knew,
put-put,
grow-grew,
take-took,
catch-caught,
come-came,
become-became,
swim-swam,
sweep—swept,
sing—sang,
draw—drew,
以上的（1）至（4）条中的发音均有改变,具体分别有/d/ /t/ /id/.
而不规则动词的过去式的发音则略有不同,但是有些还是按照一定规律变化的.如以上的：make - made,get - got ,buy - bought ,come - came ,fly-flew ,bring-brought,teach-taught,think-thought,say-said,sit-sat.read-read,spend-spent,give-gave,tell-told,write-wrote,feel-felt,find-found,hear-heard,know-knew,put-put,grow-grew,take-took,catch-caught,come-came,become-became,swim-swam,sweep—swept,sing—sang,draw—drew.