Is a trial judge entitled to question witnesses for clarification?

A trial judge is entitled to question witnesses for clarification by intervening in the testimony of witnesses. In Chippewas of Mnjikaning First Nation v. Ontario, 2010 ONCA 47, 265 O.A.C. 247, at paras. 231, 238 and 243, leave to appeal refused, [2010] S.C.C.A. No. 91, this court considered questioning by a trial judge: An examination of whether a trial judge has unduly intervened in a trial must begin with the recognition that there are many proper reasons why a trial judge may intervene by making comments, giving directions or asking questions during the course of a trial. A trial judge has an inherent authority to control the court's process and, in exercising that authority, a trial judge will often be required to intervene in the proceedings. … On occasion, trial judges may be required to play a more active role in asking witnesses questions. However, when they do, it is important that they use care and not create an impression through the questioning process of having adopted a position on the facts, issues or credibility. … All of that said, appellate courts are reluctant to intervene on the basis that a trial judge "entered the arena" and improperly intervened in a trial. There is a strong presumption that judges have conducted themselves fairly and impartially. … In the end, an appellate court should only intervene if satisfied that the trial judge's interventions, considered in the context of the entire trial, created a reasonable apprehension that the trial judge was biased.