Last night, my three year-old sat in my lap and we reviewed letters and their sounds. Sometimes she doesn't know what something is, so she asks me, "Daddy, what's that again?" My five year-old son sits with me after she does, and he works on sounding out 3 letter words like "dot" and "dog." When he doesn't know, he just guesses, hoping he's right. For instance, if we're looking at a picture of a girl and her dog and a chicken, he begins guessing based on the picture he sees below. His process isn't necessarily wrong, but his sister's lends itself to better learning.