Collect three or more items, for example pens, rulers, spectacles or mobile phones, from each student in the class. Tell the students that they have to remember who each item belongs to before placing them into a big bag. Divide the class into teams of three or four. Tell the class that you will pull an item out of the bag, but the owner of the item must remain silent. Pull an item out of the bag and ask, "Whose is this?" The first person to correctly identify whose item it is and to give you a grammatically correct sentence such as, "It is Paula's mobile phone," wins one point for her team. Hand the item to its owner and pull another item from the bag. Continue in this fashion until all the items are gone.
Prepare a list of nouns and verbs before the class begins. Divide the class into two teams and arrange the students into two lines facing the board. Read, at random, three nouns and a verb from your list, for example, "elephant," "book," "coffee" and "jump." The student at the front of each line must run to the board and as quickly as possible write a grammatically correct sentence, using these words and a singular possessive, onto the board. For example, "I jumped over the elephant's book while drinking coffee." The first student to write a grammatically correct, although probably nonsensical, sentence gains one point for her team. She now goes to the back of the line, and it is the next student's go. Continue until every student has had at least one turn at writing a sentence.
Prepare a short story with language appropriate to the level of your class and containing lots of singular possessives. Divide the class into groups of three. Read the story to your class at a normal pace. Whenever a student hears you read a singular possessive he should immediately, and loudly, repeat it to gain one point for his team. Should he incorrectly identify a plural or any other part of speech as a possessive, then his team loses one point.
Show the class a drawing of your family tree and briefly explain who some of the people are. For example, "This is Sue. She is my aunt, and she is Tracy's sister and John's mother." Ask students to draw their own family tree. Arrange the students into pairs. Each student takes a turn to ask, "Who is this?" and points to someone on her partner's family tree. The partner responds with two or three sentences using possessives such as, "This is Maria. She's my grandmother. She is also Ricardo's wife and Anna's mother." Circulate as the student's work, paying particular attention to their pronunciation of the possessive "s."