This is from an exercise in Tobira Grammar Power, you had to explain what 'bilingual' is using the というのは~ということ/という意味だ.
I wrote「バイリンガル」というのは、言葉が2つ話せるといういみです。, But in the answer key it says 2つの言葉が話せる. Obviously the answer key is right, however I vaguely remember seeing Nが[number]つV a long time ago, and it being as correct as the [number]つのNがV structure.
I'm not sure though, so is 「バイリンガル」というのは、言葉が2つ話せるといういみです。incorrect? If it isn't, does it sound unnatural compared to 「バイリンガル」というのは、2つの言葉が話せるといういみです。?