Practice the dialogue. There are six requests. Select three and circle X and select three and circle 0.
Make a pair and take turns playing both roles in the dialogue. When you make the request and if you pick one your partner has circled the 0 your partner says 'Sure' then after the dialogue ask for a sign. If you pick one with the X then your partner responds 'Sorry I can't' and you don't get a sign.
Regardless switch roles, do the dialogue a second time and then say goodbye and find another partner.
Continue until the teacher calls time up and see how many signs everyone has collected.