"A sheet of paper lies on the desk."
Translation:На столе лежит лист бумаги.
I am sorry. It is not very good, but is better what i know)) For the base of language is even good with errores of Duo, because in our language no so important the phrases constraction. Important is know the words and pronunciation. And after i think very good to take a not professional teacher in italki.com or the same serviсe, it is cheap and effective.