Try and find an accountant in Mons who speaks a modicum of English. Go on, I dare you. I tried, and failed. I worked my way through the phone book, spoke to dozens of secretaries, was promised that an accountant would call back later in the day (of course they didn't. They never do, and I didn't expect them to). In the end, I managed to get an email address, and the hope that this one spoke English.
As I've experienced several times, when people here say they speak English, they usually don't. Or if they do, they can understand far more than they can say, or just don't have the confidence to say very much. My French is usually a lot better than their English, so we end up chatting in French.
Which is exactly what I did with my accountant. Something I was hoping to avoid. Again, for things that are important, a bit technical, I just don't feel comfortable doing them in French. But, needs must.
It was one of those occasions where I could feel my whole body tensing up because I was concentrating so hard, trying to understand him. Here's a tip - I found repeating back to him what he'd just said rather handy. Something you can't really do in most everyday scenarios, but when you're paying for a service, why the hell not.
So far I've had two meetings with him, and all seems to have gone well. He'll sort out my tax returns and other relevant paperwork, find as many things I can avoid paying in tax, and I can now stop stressing whenever I receive a thick envelope every May with the incomprehensible tax return forms. To be honest, even if this was all in English, I'd still probably be clueless.