My Littlest angel needed practice in isolating initial sounds. She could word build just fine, but when it came to thinking about the initial sound in other situations, sometimes she got the initial and middle sounds mixed up and then she would get frustrated.
There are two controls built into this work. One, is that each initial sound card has only the correct number of letter cards needed for the set. Two,
is the control card itself. She loves flipping over the control card and self--checking her work. I love the way she points at the control card and restates the name of the word and then points at her work card, and restates it again (extra reading practice!)