1. -o-, -en
1.1. break
1.1.1. broke
1.1.1.1. broken
1.2. drive
1.2.1. drove
1.2.1.1. driven
1.3. speak
1.3.1. spoke
1.3.1.1. spoken
1.4. steal
1.4.1. stole
1.4.1.1. stolen
1.5. wake
1.5.1. woke
1.5.1.1. woken
1.6. write
1.6.1. wrote
1.6.1.1. written
2. -ught
2.1. bring
2.1.1. brought
2.1.1.1. brought
2.2. buy
2.2.1. bought
2.2.1.1. bought
2.3. catch
2.3.1. caught
2.3.1.1. caught
2.4. fight
2.4.1. fought
2.4.1.1. fought
2.5. think
2.5.1. thought
2.5.1.1. thought
3. a, u
3.1. drink
3.1.1. drank
3.1.1.1. drunk
3.2. run
3.2.1. ran
3.2.1.1. run
3.3. sing
3.3.1. sang
3.3.1.1. sung
3.4. sink
3.4.1. sank
3.4.1.1. sunk
3.5. swim
3.5.1. swam
3.5.1.1. swum
4. consonant + t
4.1. build
4.1.1. built
4.1.1.1. built
4.2. deal
4.2.1. dealt
4.2.1.1. dealt
4.3. feel
4.3.1. felt
4.3.1.1. felt
4.4. keep
4.4.1. kept
4.4.1.1. kept
4.5. learn
4.5.1. learnt
4.5.1.1. learnt
4.6. mean
4.6.1. meant
4.6.1.1. meant
4.7. send
4.7.1. sent
4.7.1.1. sent
4.8. spend
4.8.1. spent
4.8.1.1. spent
5. irregular
5.1. be
5.1.1. was/were
5.1.1.1. been
5.2. come
5.2.1. came
5.2.1.1. come
5.3. eat
5.3.1. ate
5.3.1.1. eaten
5.4. have
5.4.1. had
5.4.1.1. had
5.5. make
5.5.1. made
5.5.1.1. made
5.6. say
5.6.1. said
5.6.1.1. said
5.7. see
5.7.1. saw
5.7.1.1. seen