英语里越常用的动词，过去式越不规则。偏偏这些词天天见，不背不行。
小学到初中高频的就 30 来个，按变化规律分组背，比挨个记快。
AAA 型：三形一样
- cost → cost → cost 花费
- cut → cut → cut 切
- put → put → put 放
- read → read → read（拼写一样，读音变 /red/）
ABB 型：过去式和过去分词一样
- buy → bought → bought
- bring → brought → brought
- think → thought → thought
- keep → kept → kept
- sleep → slept → slept
- sit → sat → sat
- stand → stood → stood
- find → found → found
- have → had → had
- make → made → made
- say → said → said
- tell → told → told
ABC 型：三个都不一样
- go → went → gone
- do → did → done
- see → saw → seen
- eat → ate → eaten
- take → took → taken
- give → gave → given
- write → wrote → written
- speak → spoke → spoken
- fly → flew → flown
- know → knew → known
背法：做成卡片，正面写原形，背面写两式，每天过 10 张，三天一循环。一周就熟。
