Diphthongs are common in many languages, including English. For example, the English word "coin" contains the diphthong "oi" pronounced as a single sound. Another example is the word "day," which contains the diphthong "ay." In both cases, the diphthong is formed by combining two vowel sounds.
Diphthongs can be contrasted with pure vowels, which are pronounced as a single vowel sound without any change in the position of the tongue or mouth. Pure vowels are common in many languages as well, but many languages also contain diphthongs or other vowel combinations.
Overall, diphthongs are an important aspect of many languages and can significantly affect the way words are pronounced and understood.
