From
http://www.cic.gc.ca/english/resources/publications/citizenship.asp"In general, you are a Canadian citizen if you were born outside Canada and one of your parents was a Canadian citizen at the time of your birth because the parent was either born in Canada or naturalized in Canada (i.e., the parent was a permanent resident [a landed immigrant] before becoming a citizen). You are the first generation born outside Canada. For more information, please see the “First generation limit to citizenship by descent” section.
You may be a Canadian citizen if you were born outside Canada between January 1, 1947, and April 16, 2009 inclusively, to a Canadian parent who was also born outside Canada to a Canadian parent (you are the second or subsequent generation born outside Canada). If you think this may apply to you and you need more information, please contact us (see the “Contact Information” section at the end of this publication)."
Since only Canadian citizens can hold a passport, it seems nearly impossible that your husband's grandmother was not a Canadian citizen. Normally you need to formally renounce a citizenship to lose it, so even if she obtained another citizenship later she probably was still Canadian. It appears that this would make his grandfather a Canadian as well. Also, I am assuming your husband was born between 1947 and 2009, it may even make him a citizen. I would strongly recommend contacting CIC immediately about how to determine this, and to find out what procedure is in placing for claiming Canadian citizenship. Looks like you might get lucky and not have to worry about sponsoring your hubby!
