Bump. Sorry on one was able to help you.

What I would suggest is that the ginger plant has more of a spreading habit, while the canna shoots straight up. The way the leaves grow from the stem is also different but I can't describe. Try googling some pics. and compare them. It will be difficult unless you have flowers or tubers.

First, neither are true lilies - both are in families completely unrelated to the Liliaceae despite what their common names may allude to. Second, "ginger" is a common name applied to multiple genera including Hedychium, Globba, Kaempferia, Alpinia, Zingiber, Curcuma and Asarum, among others. Foliage shape, flowers and growth habit differ widely between these so impossible to make any meaningful comparisons.

I'm not sure how to explain it any more directly but it is hard to mistake a canna for any type of ginger - they just don't bear any real resemblance other than an alternate distichous leaf arrangement.