Diphthong is a vowel sound in which the tongue changes position to produce the sound of two vowels. Diphthong is a single sound produced when two vowels (one dominant in duration and stress, and one reduced in duration and stress) are paired together in a sequence. There are eight diphthongs commonly used in English . They are : / e ɪ /,/ ɑ ɪ /,/ ə ʊ /,/ ɑ ʊ /,/ ɔ ɪ /,/ ɪ ə /,/ e ə / and / ʊ ə /. It is important to note that the close combination of the two vowels causes each of the vowels to lose its pure quality. For instance, the / ɪ/ in / ɑ ɪ / is quite different from the / ɪ/ [It]. In phonological patterns, diphthongs are labeled using a single "V" (not V V) because they act as one sound. Although diphthongs are considered as a combination of two vowels, never put the length marker (:) when combine and transcribe them in phonetic symbols. Diphthongs The first vowels Closeness Frontness Rounding ...