Well, you were told you have a typo, that is not completely correct. No, you cannot tell if it is -li or -ly, that's why all have to be supported and why the audio exercise has to be disabled. Was it an audio exercise by any chance? If it is not disabled already I will disable it right now.
The main point is - always report the complete sentence when asking here. When it was some special kind of exercise (audio, form selection), tell it as well.
Vyžaduje to to "not once" na začátku.
we also sometimes use inversion in other cases, when we are not making a question."