When I started work at my present company, my job was to have developers explain what they had just built in the software, generally esoteric technical concepts. I was simultaneously listening, thinking/mentally translating what the developer SAID into something I could fit with all my other knowledge, and taking notes. I found that sometimes, if I had understood the concept correctly, I would have a question about how some part of it worked, and I would have to stop to translate the question into English.

Given that English is my native language, that got me wondering about what language I was *thinking* in. The best I (and friends) can come up with is: symbols. So in my case, if English is limiting (the *developers* certainly don't use what I would consider understandable English), I don't use *language* at all.