Are All Regular Languages Decidable?

All decidable languages are recursive languages and vice-versa.

How do you know if a language is recognizable?

A language L is recognizable if and only if there exists a verifier for L, where a verifier is a Turing machine that halts on all inputs and for all w∈Σ∗, w∈L↔∃c∈Σ∗. V accepts ⟨w,c⟩.