As verbs the difference between Tell and affirm
is that
Tell is to count, reckon, or enumerate while
affirm is to agree, verify or concur; to answer positively.
As a noun tell
is a reflexive, often habitual behavior,
especially one occurring in a context that often features attempts at deception by persons under psychological stress (such as a poker game or police interrogation), that reveals information that the person exhibiting the behavior is attempting to withhold.