Just 25 most commonly used words make up about one-third of all words written or spoken in English. The first 100 most frequently used words make up about one-half of all written and spoken English. These are the most commonly used and most important words when it comes to understanding and creating correct sentences. By the end of this series, the child will have learned to read and understand all of the most important English words and structures. At this point, the child will be functionally literate and fully capable of independent reading.