Ebook Spelling practice book Grade 1 helps you know short vowel /a/a; short vowel /i/i; digraph /k/ck; short vowel /o/o; variant vowel /ô/a (all; short vowel /e/e; digraph /th/th; short vowel /u/u; diphthong /ng/ng; digraph /sh/sh; digraphs /ch/ch, tch; digraphs /kw/qu, /hw/wh;.