I am currently a Canadian Citizen but wanting to attain Dual Citizenship. I was born in Canada and moved to the U.S when I was 2 with my family and was considered an alien resident. We lived there for 11 years (from 1987 - 1998) and moved back to Canada and was given the choice to have U.S citizenship OR Canadian citizenship and my parents chose Canadian for me but now that I am older I want to know if its possible to attain dual? My mother is American by the way!

If your mother is American, it's likely that you can claim citizenship through her, but your story is not clear as many details are missing here. It's well advised that you should consult immigration attorney with all documents you have.