The words I was bothered to think about that do not have a vowel is 'why', 'sly', 'try' and 'fry'. And 'why' could be a sentence in its own right? Although many would argue against that I believe 'Why?' is a sentence even though it is said that all sentences must have a verb. All these words end in 'y' because 'y' can have the vowel sound 'i' but it is not a vowel.
To conclude I would say that there a words and sentence(s) that do not possess a vowel.
no 1
Aeiou - 2002 is rated/received certificates of: Spain:T
Vowel
Vowels
syndy
Rhythm
facetious abstemious arterious
Y
Sky?
Torquay united
sylph
Mozambique