Your turn 1 of 2
F major and F minor share the exact same tonic note, F, and a listener can move between them without changing where home sits. Why isn't the parallel minor counted as a closely related key even though it shares a tonic? Closely related keys are defined by how few accidentals separate their key signatures, one accidental away at most, and a parallel minor's signature differs from its parallel major's by three accidentals, too many to count as closely related. Closely related keys are defined entirely by sharing a tonic note, so any two keys built on the same letter, such as F major and F minor, automatically qualify as closely related to each other. The parallel minor counts as closely related, and the rule that closely related keys differ by only one accidental is a rough guideline overridden whenever two keys share a tonic. F major and F minor are not closely related because they use different tonic notes once the key signature is taken into account, even though both are labeled with the letter F.