yes... yes it should... but if you put a "!" after "engleza" it's correct because it's an order, because it puts emphasis on what not to speak... not on just speaking
i guess it's like 'the english' apparently you could say: limba engleză or engleza
"No, do not speak English" and "No, you do not speak English" are very different sentences yet they are both accepted as answers. Why?
I think that it's because it's supposed to be sort of saying that you aren't to speak English. Like, No! Don't speak English, you! Please correct me if I'm wrong.