| Note in parentheses that diphthongization may be viewed in a similar light. |
| Also, diphthongization in modern dialects has been leveled due to the widespread use of standard language. |
| Nonetheless, a number of studies suggest that at least diphthongization and nasal and lateral depalatalization may be unproductive in Spanish. |
| Vowel breaking or diphthongization is a vowel shift in which a monophthong becomes a diphthong. |
| The long u is absent because diphthongization into ui is a common feature of the North Estonian dialects. |
| Only Lorrainian and Low Hessian, of all the Rhine Franconian area, remained unaffected by diphthongization. |
