一般过去时变化规则
(1) 一般在动词后加-ed。
如：play—played, offer—offered, weigh—weighed,
Destroy— destroyed, sign—signed.
(2) 在以字母 e 结尾的动词后，只加-d。
如：like—liked, provide—provided, hate — hated, date—dated。
(3) 在以“辅音字母+y”结尾的动词后，则改 y 为 i，再加 ed。
如：supply—supplied, fly—flied, study— studied.
(4) 在以单短元音的重读闭音节结尾且末尾只有一个辅音字母的动词后，双写最
后一个辅音字母，再加-ed。
如：plan—planned, refer—referred, regret—regretted, ban—banned.
★重读闭音节三要素：（1）一个元音字母后跟一个或几个辅音字母
（2）以一个辅音音素结尾；
（3）元音字母发短元音。
★长元音 ：[i:][ə:][a:][ɔ:][u:]
短元音 ：[e] [i] [ʌ] [æ][ə][ɔ][u]
常用不规则动词分类表
⒈ A---A---A 型（现在式、过去式、过去分词同形）
cost cost cost 花费 cut cut cut 割，切 hit hit hit 打
let let let 让 put put put 放下 read read read 读
hurt hurt hurt 伤
⒉ A---A---B 型（现在式和过去式同形）
beat beat beaten 打
⒊ A---B---A 型（现在式和过去分词同形）
come came come 来 become became become 变
run ran run 跑
⒋ A ---B ---B 型⑴在动词原形后加一个辅音字母 d 或 t 构成过去式或过去分词。
burn burnt burnt 燃烧 learn learned/learnt learned/learnt 学习
mean meant meant 意思 hear heard heard 听见
⑵把动词原形的最后一个辅音字母“d”改为“t”构成过去式或过去分词。
build built built 建筑 lend lent lent 借给
lose lost lost 失去 send sent sent 送 spend spent spent 花费
⑶其他
pay paid paid 付 lay laid laid 下蛋 say said said 说
bring brought brought 带来 buy bought bought 买
think thought thought 想 catch caught caught 抓住
teach taught taught 教 fight fought fought 战斗
sleep slept slept 睡 keep kept kept 保持
sweep swept swept 扫 stand stood stood 站
understand understood understood 明白 win won won 得胜
shine shone/shined shone/shined 发光 feel felt felt 觉得