Board Thread:Questions and Answers/@comment-4547267-20161112192256/@comment-7218858-20161112195501

Case 1 (If All Might has other quirks): All Might can fly and Izuku cannot, why is this? Although, All Might hadn't shown any signs of any other quirk.

Case 2 (All Might doesn't have any other Quirks): Maybe Quirks don't transfer, its just the One for All Quirk that does.

Case 3 (All Might doesn't have other Quirks, but has their strength combined): I believe it has been sated before that One for All keeps getting more powerful from every previous user.