Submitted by joanneleclair on June 23, 2021, at 16:44
Although Canadian spelling tends to favour the double “l,” there are exceptions. According to the Canadian Oxford Dictionary, the preferred spellings for the examples you gave are “fulfill” and “instill” (with a double “l”) but “skilful” and “enrol” (with a single “l”). The best thing to do is to pick a reliable Canadian dictionary and use it consistently. For more information on Canadian spelling, see the second part of the Portal’s writing tip called “spelling: international variations” (https://www.noslangues-ourlanguages.gc.ca/en/writing-tips-plus/spelling-international-variations).