This document defines and provides examples of diphthongs. Diphthongs are vowel sounds that transition from one vowel sound to another within the same syllable. The document lists the most common English diphthongs (/eɪ/, /aɪ/, /ɔɪ/, /ɪə/, /eə/, /aʊ/, /oʊ/) and provides example words to demonstrate how each diphthong is pronounced. It notes that pronunciation of diphthongs can vary between dialects. The purpose is to help readers understand and correctly pronounce diphthongs in English.