This book introduces the dummy subject “IT” with to-infinitives in sentences. Young readers explore different units of time, such as seconds, minutes, hours, days, weeks, months, years, decades, centuries, millennia, millions of years, and billions of years, in relation to their daily actions and significant historical events. The main sentences in the book, “How long does it take you to do ~?” and “How long did it take to do ~?” help children become familiar with the structure of the dummy subject ‘it’ followed by a to-infinitive.