Translation:The hardworking boy speaks French and Finnish.
What is wrong with?.... The hardworking boy is speaking French and Finnish.
There are example after example where "plays" or "is playing", "cries" or "is crying", etc. etc. are both acceptable answers.
Perhaps the boy is actually speaking both French and Finnish in a 3-way conversation. Or when he can*t think of the Finnish word uses the French word instead?
OK, so now I must ask: the English obviously refers to the ability of the boy to speak, so in effect the sentence reads "the boy is able to speak french and finnish." Just, in English, you understand that this sentence reports a capability. Obviously, else the sentence would imply that he would be simultaneouly speaking the languages... obviously not!
But in Finnish we have been trained to use 'osaa' when we report an ability. So does this sentence mean to a finn that the boy is just now speaking both languages? Or, is it like English, and the finn understands automatically that we are discussing an ability of the boy?