When I work with Genitive/possessive case I like to pick up some students � objects and put them into a bag or on my desk. I usually work  school objects because they have already studied.

Then I show one of the objects and ask them: Whose pen is this?

Students answer: It �s Maria �s pen.

Whose �s ruler is this? It �s Pedro �s ruler.

First practice singular.

 

Then I take two pencils and ask again: Whose pencils are these?

Students answer: They �re Bill �s pencils.

I usually work the singular in one class and plural in another day.

 

I continue until I finish the objects. It is simple but very practical. They like and have fun.

 

 

 

 

You might like to compare the clothes of people who do different kind of jobs. Take hats for example, a policeman, a chef, a builder, a pilot all wear different kind of "hats". Show them some pictures and ask them whose they are. Good luck !!!

I also use Ju10 �s idea, but at the end of the lesson, to make sure they understand both Whose and The Genitive, I ask students to give me one of their objects (and you may substitute for pieces of cloth) and put all of them in a bag. Then, each student picks one of the objects up and ask "Whose ... is this/are these?". The other student �s have to say "It �s/They �re ... �s ..." I also do it as a competition. My students from Brazil get crazy. The children always ask me to play the game again! :)

Hope it �s helpful.