You almost surely can. If it is truly a gift card (someone bought it for you with cash) it is as good as cash; in fact, almost every store will let you turn them in for cash if you want (some people don't realize this-- if you get a gift card at a store you hate, you can just cash it in). It's essentially a free loan for the store chain, so they love these; plus most people do actually use them at the store chain that issued them.
Really??? This I did not know, and now I could of used those for something good. I will have to try this out.