Yes, for 1 cup of regular flour you can replace it with 2/3 cup of potato starch[ not potato flour] and 1/3 cup of soy flour. Do not over beat, just very briefly blend because the starch can get rubbery. It is my favorite combo for cakes.Makes nice light cakes. Sorghum flour makes nice cakes.

its not that hard the potato's

I be a farmer

No, they are not the same. They are both starches and can be used as thickening agents, but they come from different plants. Each has different thickening capabilities and they have different flavors.

Potatoes are grown in acres and acres of fields, and then are picked and transported to a processing plant, where the potato is bathed in anti-bacterial solutions that do not affect the potato, and cleanse the potato, and get packaged and shipped off to be sold at a store.