To really know English one has to master, along with grammar and words, a reasonably large vocabulary of recurrent collocations, id- ioms, and metaphorical expressions that reflect the environment, history, and culture of the na- tive speakers and form an essential part of their common language, adding color, dimension and vibrancy to the way they speak and write. Fa- miliarity with idioms and colloquial metaphors and ability to use them appropriately in context are distinguishing markers of a native-like com- mand of English. Learning a language is challenging enough while learning set expressions (a language- within-a-language) becomes really frustrating at times, not the least owing to the existence in En- glish of a very vast number of what we call phraseological “false friends and enemies”—id- iomatic and non-idiomatic expressions that, de- spite their outward similarity or contrast, have unrelated meanings. Their confusion triggered by false analogy may result in misunderstanding and miscommunication so knowing or not knowing the difference between phraseological “false friends” can mean the difference between understanding or not understanding English. This dictionary has been specifically de- signed to “diffuse” potentially confusable expres- sions. The dictionary pairs more than 10,000 id- ioms and collocations characterized by similarity or contrast in their wording or metaphorical idea that do not show corresponding similarity or contrast in their meanings. Also included are cases when phraseological units form a semantic mismatch with consonant compound words. This contrastive format enables the language learner to see all potentially confusable units to- gether and so avoid confusing the phrase. Most dictionary entries are made up of phrases that are in active current use so infor- mation about the difference in their meanings and usage is especially essential. Some entries may contain phrases pertaining to professional jargon, slang, expressions that are dated or char- acteristic of one the principal regional varieties of English. These, though less relevant in terms of their confusion, demonstrate interesting cases of coincidence in imagery through time and space while their contribution to the dictionary allows it to be also used as a regular explanatory dictionary providing definitions to individual idioms, clichés and set expressions. There are numerous dictionaries of usage covering the difference in the meaning, spelling and pronunciation of lexical “false friends”—ho- mographs, homophones and semantically unre- lated words characterized by outward similarity. This comprehensive dictionary, however, repre- senting as it does an important cross-section of the language, is unique in that it is the first at- tempt ever to provide a complete lexicographic inventory of phraseological pseudo-synonyms and -antonyms, both idiomatic and non-idio- matic. Intended primarily for ESL students at dif- ferent levels of proficiency, the dictionary can Preface –1–