In categorical propositions a quantifier normally ranges over instances of the subject: “Every human is an animal.” In conditionals the concern is the scope of suppositions or circumstances in which the antecedent and consequent are considered.
“Whenever the sun rises, daylight exists” extends the connection beyond today's particular sunrise to the relevant cases generally.
Thus conditionals also admit singular, quantified, and indefinite forms, but their quantification must be analyzed in the appropriate domain.