The English phonetic also includes an array of 5 diphthongs or gliding vowels : 3 y-colored diphthongs and 2 w-colored diphthong. The diphthongs behave as a single vowel, despite the glide at the end of them.
It's important consider the diphthongs, like the monothongs and the rhotic vowels, can vary their pronunciation, depending the dialect, recording and stress of the word.
- Example: The diphthong [eI] can be pronounced with different degrees of stress, being realized either as [eː] (unstressed monothong), [eɪ] (diphthongized [e], lax glide), [ei] (diphthongized [e], tense glide) or [ej] (diphthongized [e], short tense glide). Big Al is know to vary noticeably the pronunciation of this phoneme accord the context.