"You are closing the bag."
Translation:Tú cierras la bolsa.
"cerrá la bolsa." This was given as a solution on 11/03/2018 but there was no appropriate option to report it.
"Tu vas a cerrar la bolsa" was the correct answer that Duolingo provided to me when my own answer was wrong. (On June 5th 2018). I'm confused since this answer seems to be in the future tense (You are going to close the bag).
The present progressive tense in English can be used to refer to the future, that's why.
To form the present progressive in Spanish, combine a form of “estar” with the present participle.
Informal you. "Tu estás cerrando la bolsa."
Formal you singular."Usted está cerrando la bolsa"
From a reliable source here.