Here's why:
* Phoneme: A basic unit of sound in a language. Vowels are phonemes.
* Syllable: A unit of pronunciation that typically has a vowel sound at its core.
* Morpheme: The smallest unit of meaning in a language. While some morphemes can have one vowel phoneme (e.g., the word "a"), they are not the smallest unit of speech with a vowel phoneme.
Example:
* The word "cat" has one syllable, and the vowel phoneme is /æ/.
* The word "book" also has one syllable, and the vowel phoneme is /ʊ/.
Important Note: While a single syllable can have one vowel phoneme, some syllables may have more than one vowel phoneme (e.g., the word "boy" has the vowel phonemes /ɔɪ/).