“Whiskey” is used for whiskeys made in Ireland and North America. “Whisky” is used for those made in Canada, Japan, Scotland, and Wales. Your best bet is to go by what’s on the label of the bottle. (For example, Maker’s Mark is labeled as bourbon “whisky,” even though it’s made in Kentucky.) Though “scotch” has become ubiquitous, it is simply known as “whisky” in Scotland.