No. 'Adverbial' question words such as Ble/Lle, Pam, Sut, Pryd? (where, why, how, when?) are always followed by mae..., bydd..., roedd..., etc rather than by ydy/yw..., fydd..., oedd..., etc. (Althought the r- in forms such as rwyt, roedd, etc is sometimes dropped in speech.)