Are you trying to learn English but don't know where to begin or what to study? Have you ever learned a new word but forgot it the next day? These two problems can be solved by science. The first science looks at the number of words in a text. There are 300 words in this description. The most common word, THE, has a coverage of 8% because it appears 24 times and covers 8% of the words in the description. The next most common word is the verb BE. Its count of 21 includes all its inflected forms (for example, is, are, was, and were) so it has a coverage of 7%. The combined coverage of THE and BE is 15%. Coverage is important because it tells you two things. First, it tells you if you are likely to understand a text. You need to know at least 95% of the words in a text to be able to read it without a dictionary. Second, it tells you which words you need to study to get to that 95%. Not all words are equal. Some words are more important than others when you begin to learn a second language, and the word's coverage tells us how important it is. The words on the New General Service List are the most important words based on this research into coverage. The second problem can be solved with the science of memory. This research tells us the best way to remember something is to repeat the learning at increasingly longer time intervals. In other words, you need to look at the words many times at different times. This puzzle book uses the same words in different puzzles. As you work your way through the book, you will meet the words many times. This will help you to remember their meanings.