This book illustrates the key aspects of English phonetics and morphology, bearing in mind that competence in these two fields facilitates the mastering of language at different levels: spelling, vocabulary, pronunciation, fluency, word recognition, origin and structure of words and, overall, text comprehension. Phonetics is the branch of linguistics that studies the sounds of human speech, how they are produced, transmitted and perceived. In turn, morphology analyses the structure of words and their parts, such as stems, prefixes, and suffixes, with special focus on the differences between derivational and inflectional affixes. Competence in these two branches of English linguistics is the first step in the full mastery of English.