"Gwnân nhw ddysgu!"

Translation: They will learn!

[Tom.Pegley]

Is "Gwnân nhw ddysgu" the same as "Byddan nhw ddysgu"?

[EllisVaughan]

Yes, though you need it to be "Nhw'n" in the "Byddan nhw'n dysgu" construction (and also note no mutation in that construction either) because "yn" (when it is a verbal particle) is needed to connect a form of bod (in this instance "byddan") to a noun, verb-noun or adjective (in this case the verb-noun "Dysgu"). "Byddan nhw'n dysgu" is already accepted as an answer.