In the drill "えいご_はなしません。", I had the options to answer, among others, で and を. I chose を and was marked down as wrong, the supposedly correct answer having been で, but I am sceptical.
Yes, "えいごではなしません。" is a correct sentence, translating to "I don't speak in English.", but is "えいごをはなしません。" not also a correct sentence, as in "I don't speak English?" Or does はなします necessarily require the particle で?
And if "えいごをはなしません。" is not a correct sentence, how else would you say "I don't speak English."?