'a', 'Asthma' (I know it has two but if it's a riddle you're talking about, it will try to trick you; 'a' and 'a' are the same vowel)
An open syllable is a syllable that ends in a vowel sound, typically making a long vowel sound. Examples include "be" and "to."
stir
'Example' has 3 syllables and ends with a vowel.
apple
There are thousands of English words with only one vowel.The words I and a consist of only a single vowel.
technically careful is not a base word, the base of careful is care, which ends in a vowel.
strengths
Stretch is a 7 letter word with e as the only vowel. Twelfth is another 7 letter words containing only one vowel.
The word "rhythm" does not have a vowel, or end in the letter y.
Some words with only one vowel are:aanantasaskaspatbadbangbathbedbestbetberthbirchbirthblendblindblondblotblotchblownbringbrownchampchickchirpchurnclampclerkclickclockclothclumpcrownditchdrilldrinkdrolldrownerrfifthflirtfrontgirthglassglintgrassgrindhatchhitchhunchhutchIininchinkinnisititchkingkitknackknightknockknownlamblampletlightlimplisplitlynchmompinkpopshirtshortslackslantslickslothslumpspankspellspillsportspurnstampstandstartstringthingthirstthriftthornthrusttrustwantwellwillwiltwishwarnworkwornyakyamzinc
No. Vowels are letters, so the only words that can be vowels are words consisting of only one letter, such as "I" or "a". The word "said" is a verb.
aioli