The phonemic chart maps every distinct sound in English to a single symbol (the International Phonetic Alphabet, IPA), which matters because English spelling is a poor guide to pronunciation — the letters “ough” alone are pronounced differently in “though,” “through,” “cough,” and “bough.” CELTA candidates are expected to read and use the chart to mark word and sentence stress in lesson materials. This is consistently one of the more intimidating parts of the course for new candidates — spend time before you start simply reading the chart aloud and matching symbols to sounds you already make naturally.