The seventh stage commonly occurs between 40-60 months, depending upon attention span and interests. Most children are more physical and imaginative in Stage 7, and they use language to express these characteristics. Even at this point, with extensive verbal experience, few children have full mastery of all sounds in the language, so rich vocabulary and experiments with silly words are a form of practice. Their grammar is developing but still far from perfect, and they continue to be insatiably curious, asking more questions and demanding more explanations than at any other stage. Illustrations, though still enjoyed, are no longer essential to all reading experiences.