Unit 1 - ch, ch, sh

Unit 2 - ph, gh, gh

Unit 3 - wh, th, th

Unit 4 - gn, kn

Unit 5 - ng, nk, ck

Unit 6 - mb, mn, wr

Unit 7 - ci, ce, cy

Unit 8 - ge, gi, gy

Unit 9 - qu, ve, dge

Unit 10 - bl, cl, fl, pl

Unit 11 - cr, dr, gr, tr

Unit 12 - sk, sp, sn, sw