Entry Definition
(response to a question) yes; (introducing a statement or conclusion) yes
certainly, surely, for sure; (when the answer "no" is expected or when disbelief has been expressed by the other speaker) yes, why yes!, on the contrary; (following if or if not) then (see examples)
that's true
yes, go ahead; yes, let's proceed (Pesk)
(introducing or concluding a statement, especially when telling of a remembered experience) yes, yeah