do we have in English a ward that doesn't has a vowel
what do you mean?
I had just written this, black cat, when I saw this site, and , of course, I know these words:
Words without vowels - Wikipedia, the free encyclopedia
Look, these are only some of them:
by, cry, sky, why, gym, crypt, hymn, lynx,
I think though, the letter y is considered a half-vowel.
Perhaps ‘mhm’ for <yes> and ‘hmhm’ for <no>?