The French language and English language are the official languages, but you have interpreters. If someone comes from Asia or Eastern Europe and they don't speak English, the trial does not proceed unless there's an interpreter. The interpreter interprets. That's true through all the courts. It's most important, however, at the trial court, where the evidence is presented and he may want to testify and so on and so forth.
When you get to appeal courts, you're generally dealing with some question of law. Frequently, the accused person or the parties to the lawsuit don't bother to show up. The lawyers are there, but not the parties.
There's nobody in a Canadian court who stands trial and who is not entitled to an interpreter.