My kids have rhyming down, and blending onsets and rymes. Now I want to work on segmenting onsets/rymes and naming the beginning sound. They can tell me the first sound in their name, but that's as far as they can go. They cannot, for example, name a word that starts with a given sound, or tell me what sound a word starts with. How do you teach this? What games/songs are there that teach this?