The easy answer is yes, with a BUT. Floppy ears can be corrected. If the ear is straight, but laying to the side or on top of the head, yes, it is possible to correct with minimal surgery... a few snips or sutures, depending on the ear.  There are also implanted stays that can be put under the skin of the ear in the case of injury, broken cartilage ect, or for an ear that folds over. It is much harder to find a vet that will implant stays in the dogs ear than a vet that will do a little 'nip/tuck' to get an ear to stand true.Â
As an adult, the ear cartilage has set. You only have time through the dog's transition from puppy teeth to adult teeth to get the ears taped properly and standing. The cartilage stays soft and flexible while the teeth are changing, but after the adult teeth come in, the cartilage hardens, and becomes fixed for all intents and purposes.Â
You may have seen Dobes, Danes or Boxers at dog shows with thier ears taped up before going into the ring. These dogs have been cropped for the long elegant show look, and being such big breeds, the ear leather is heavy, and some dogs have a tendancy for their ears to curl back or forward at the tips. The taping is just a temporary fix, and has no effect over the long term.Â
I have a Giant Schnauzer with a show crop, her ear leather isn't so heavy that I need to tape the tips. However, there is always SOME curling of the ears as the cartilage sets, but it adds to the elegance of the ear.
Hope this helps. A cold wet nose in the morning with coffee is heaven, regardless of floppy ears or not.