I am getting quite mixed results with speaking English in court.
Some court clerks tell me speaking English in court will be disaster -- that non-French speakers must hire an interpretter who is certified for court. Cannot bring a friend for this purpose. Even social interpretters who work gratis in a public service capacity are useless for court proceedings. Certified interpretters tend to charge €200/hour (more than some lawyers).
A clerk who works for a particular judge said “the judge is not hard and will speak English”. And it turned out to be true. There was no resistence to English.
In another situation, the judge/magistrate/mediator (not sure which) spoke to me in low near-whisper and said they are not supposed to speak English, but then spoke English, somewhat insinuating/implying that it was a favor to me.
Another situation: a judge/magistrate/mediator/lawyer (no idea what capacity) said it’s a French process and French will be spoken. I was sure I would be stuffed if I knew zero French. Using my dysfunctional French seemed to be essential for things to move forward but slowed down the discussion to a point where they conceeded and spoke English briefly at moments then went back to French.
Someone with no legal background said (with confidence) that if you do not speak the official language of the court, judges actually have an obligation to speak to you in your language if they can. Of course if a civil court judge cannot speak your language, you’re naturally stuffed.
So in Belgium, clerks are in contradiction, rumors are in contradiction, and actual experiences are inconsistent.