When a shift occurs from one vowel sound to another, it is:AMonophthongsBDiphthongsCCardinal vowelDPure vowelAnswer: B. Diphthongs Read Explanation: A diphthong is a vowel sound in which there is a gliding movement from one vowel position to another within the same syllable.It's a single sound but made up of two vowel qualities.The tongue shifts during articulation.🗣 Examples in English:DiphthongExample WordSound Movement/aɪ/myfrom /a/ to /ɪ//eɪ/dayfrom /e/ to /ɪ//əʊ/gofrom /ə/ to /ʊ/ Read more in App