How many syllables does choir have?

The Word "choir" can be either one or two syllables, because the O and the I (while not a vowel pair as in "oy") can be pronounced together as a long I.

The one-syllable version is the same as "quire" with a KW sound from the QU.

This rhymes with "lyre."

The two-syllable version is (kwy-ur) with the R having a schwa sound as in "liar."

* Lyre and liar are homophones in US English.