What is the legal test for a question of law and what is the test of mixed law and fact?

The first issue is whether the proposed appeal raises a question of law. In my view it does. That is because this case is about statutory interpretation. Questions of statutory interpretation generally involve questions of law: Southam v. Director Investigation and Research, 1997 CanLII 385 (SCC), [1997] 1 S.C.R 748 at para. 36. In that case, Iacobucci J. explored the distinction between a question of fact, a question of law, and a question of mixed fact and law: … Briefly stated, questions of law are questions about what the correct legal test is; questions of fact are questions about what actually took place between the parties; and questions of mixed law and fact are questions about whether the facts satisfy the legal tests. A simple example will illustrate these concepts. In the law of tort, the question what "negligence" means is a question of law. The question whether the defendant did this or that is a question of fact. And, once it has been decided that the applicable standard is one of negligence, the question whether the defendant satisfied the appropriate standard of care is a question of mixed law and fact.