20 different books, 4 at each stage, introducing adjacent consonant
Set 11: ch
Set 12: sh
Set 13: th
Set 14: ck, wh
Set 15: ng, qu
20 different books, 4 at each stage, introducing adjacent consonant
Set 11: ch
Set 12: sh
Set 13: th
Set 14: ck, wh
Set 15: ng, qu