常见动词过去式过去分词的变化规则
动词过去式和过去分词有规则变化和不规则变化两种。
一、规则变化:
1. 一般情况直接加ed,如ask—asked, work—worked
2. 音乐会英语以不发音的e结尾,只加d,如love—loved, dance—danced
3. 辅音字母加y结尾,把y变为i,再加ed,如try—tried, study—studied
4. 以一个元音字母和一个辅音结尾的重读闭音节结尾的动词(以重读闭音节或r音节结尾而末尾只有一个辅音字母),先双写末尾这个辅音字母,再加ed,如stop—stopped, permit—permitted
注:A. 以l结尾的动词,尾音节重读时,双写l,如control—controlled;尾音节不重读时,双不双写都可以,如travel—traveled(美) /travelled(英) 。
study的过去分词B. 特例:picnic—picnicked—picnicked(去野餐),traffic—trafficked—trafficked(交易,在…通行) 另外,还有很多动词的过去式和过去分词是不合乎上述规则的,需要熟记.(见后)
C. 读音与说明:
.-ed在清辅音音素后发音为[t]: helped, liked, finished, fetched, stopped, clapped
②.-ed在浊辅音和元音后发音为[d]: believed, changed, planned, preferred, followed, stayed
③.-ed在[t]、[d] 后发音为[id]: wanted, needed, admitted, permitted
二、不规则动词(Irregular Verbs)的过去式大体上归纳有以下记忆法: 
1. 归唐以t结尾的词,过去式与原形相同。如:
安全生产会议讲话
put—put, let—let, cut—cut, beat—beat   read—read  must--must 
2. 以d结尾的词,把d变成t。如:
尾牙是什么意思
build—built, lend—lent, send—sent, spend—spent 
3. 以n结尾的词,在词后加t。如:
mean—meant, burn—burnt, learn—learnt 
4. 以ow / aw结尾的词,把ow / aw变成ew。如:
blow—blew, draw—drew, know—knew, grow—grew  throw—threw(动词show除外,show—showed) 
知识5. 含有双写字母的词,将双写改为单写,在词尾加t。如:
keep—kept, sleep—slept, feel—felt, smell—smelt  sweep—swept 
6. 含有元音字母o / i的词,将o / i变成a。如:
come—came  become—became  sing—sang, give—gave, sit—sat, drink—drank
7.以ought和aught结尾,且读音是〔 :t〕的过去式。如:   
bring—brought,buy— bought,think—thought,catch—caught,teach—taught
8.把重读开音节中的i改为o,变成过去式。如: 
drive—drove,ride—rode,write—wrote
9.动词原形中的e改为o,如:  get—got,forget—forgot
10.动词原形中的ee改为e,如:  feed—fed,meet—met 
11.动词原形中的eak改为oke,如:  break—broke,speak—spoke
12.动词原形中的ell改为old,如:   sell—sold,tell—told 
13.动词原形中的an改为oo,如:   stand—stood,understand—understood 
14.以ould结尾且读音为〔ud〕的情态动词过去式。如: