- The authoritative guide to American English as it"s really used today.The Cambridge Dictionary of American English Student Activity Book helps students find their way around a dictionary. The 21 study units in the Activity Book are designed to help users make the dictionary work for them by explaining special features of CDAE, how information is arranged in an entry, and how to access it. Exercises in the study units cover basic dictionary skills, such as interpreting grammatical information, using the guidewords to find a meaning, and applying the pronunciation key.