What are Diphthongs?
Vowels in English pronunciation are classified in two different groups: Simple Vowels and Complex Vowels. Simple vowels refer to phonetic vowel characters made up of just one symbol. On the other hand, complex vowels can be easily identified because they are made up of two phonetic characters.
| Simple Vowels | Complex Vowels |
| /ɪ/ | /iy/ |
| /ɛ/ | /ey/ |
| /æ/ | /ay/ |
| /ʌ/ | /aw/ |
| /ǝ/ | /uw/ |
| /ɔ/ | /oy/ |
| /ʊ/ | /ow/ |
Complex vowels are also referred as diphthongs. Whether we use the term complex vowels or diphthongs, we are talking about the same group of vowels.
Informally speaking, so to say, we have paid attention to two complex vowels: /ay/ and /aw/. We will eventually go back to them, but this lesson will be devoted to /oy/ and /ow/.
