Heinles Newbury House Dictiory of American English is the first learner?s dictiory developed from an American English corpus of headwords, definitions, and sample sentences. The core of the dictiory is based on an intertiolly agreed upon corpus of 40,000 head-words used by American college educated speakers of English. Written initially by a lexicographer with a MS in TESOL, a large group of ESL and EFL teachers refined each entry and sample sentence with the criteria ´will my students understand this and will they benefit from it´? This process produced definitions that are composed in an easy-tounderstand, limited vocabulary, and the sample sentences are designed to show how the words and expressions are actually used in everyday life.