Spanish /uj/ only appears in
muy 'very', and, in some dialects,
cuy 'guinea pig' (plural:
cuis or
cuyes). Some speakers report having /wi/ for these words, but for me
muy and
fui 'I was' definitely don't rhyme.
Some male Latin Americans have [ˈsə] as an alternative pronunciation of the interjection
sí 'yes', but not the adverb
sí '
EMPH' (
sí lo hizo 'he did do it'). [ə] is nothing surprising for "highland" dialects, but the thing is that this [ə] for the interjection
sí is stressed, and often enlongated in celebrations (i.e. [sə:::]). On the Internet you generally see it spelled "seee".
Mexicans and Central Americans have [ˈbɾuʃo, ˈβ-] as an alternative pronunciation of
brujo 'shaman' (also applies to
bruja 'witch', but I've never heard it for
brujería nor
embrujado). [ʃ] occurs elsewhere in these dialects in words from English and Nahuatl / Pipil, as well as the interjection
¡osh! 'urgh! (expressing disgust)', but
brujo is its only instance in native vocabulary outside interjections. If you think I'm making this up, here's
an attestation from the movie Bruce Almighty: at 2:15 you can hear
this is some bru[ʃ]o men, ¡vámonos! 'this one is a shaman, guys, let's get out of here!'
Male Salvadoran Spanish speakers sometimes pronounce the sentence-final particle
¿va? 'don't you think?' with [ɑ]: [bɑ]. (This particle also has the forms
veá,
vedá (for old speakers), and
verdad).
Va is sometimes also used as an interjection meaning 'alright!, good!', equivalent to
¡vale! in some other dialects.
In Taiwanese standard Mandarin, the triphthong /jaj/ only occurs in one word: 崖 yái 'cliff' (pronounced yá in PRC standard Mandarin).
Alon wrote:Arabic /ɫ/ only appears in Allah's name, no?
Correct.
Almost every language I've studied seems to has at least one hapax phonoumenon: English
yeah (mentioned by Nortaneous above), Spanish
muy/cuy, (Taiwanese) Mandarin yái, Arabic ’allāh, Latin
cui/huic. It seems like something that should be unremarkable, except linguists don't talk about this.
I can't think of anything good for French, but an unpredictable long /øː/ [øː] is reported by
le Trésor de la langue française to occur in less than 10 words (
jeûne 'fasting' (contrasting with
jeune 'young'),
meule 'grindstone',
émeute 'riot',
veule 'sluggish/lazy [person]',
neume '
neume').