Thank you, Barb_D!
Though it seems a litle bit strange to me to talk about home assignment in general. If I just mention "an important assignment", my students may not understand what exactly I mean (they are given important assignments at every lesson, and some of the sdtudents don't manage to do them on time, so they can do them at one of the following lessons. That's why I usually need to specify the "old" assignments by saying what exactly I want.
So, can you think of some better way of saying "Now I want you to "present" your monologues?" ( just like "Now I want you to act out your dialogues.")?