As nouns the difference between wail and wai
is that
wail is a prolonged cry, usually high-pitched, especially as of grief or anguish while
wai is a Thai greeting wherein the palms are brought together in front of the face or chest, sometimes accompanied with a bow.
As a verb wail
is to cry out, as in sorrow or anguish.
As an adverb wai is
why a purposeful misspelling.
As a conjunction wai is
why a purposeful misspelling.