Start of with the video the other poster suggested, but stop halfway. Use it as bait and tell them if they are good, you'll show the rest of the video later. Explain today's vocab (may/can/could I) and ask for volunteers, or pass a ball around etc.
Then it's time for codebreaker. They LOVE this game. After a while you need to give handicaps to certain teams as they are too good. I gave 1 sheet of paper per group and made them work together, but rotated who was writing every time. So even if the smarted kid is figuring it out, the low level students still participate in writing. If they are too slow, only for 1/2 the worksheet and move on.
Finally have them complete the worksheet. Tell them they have to be funny. This will result in many "May I be your boyfriend?" "May I kiss you?" "May I see your poo?" "Can you punch me" etc. Then randomly select 2 students and have them ask answer questions. The students need to answer correctly "Of course/No way". Students enjoyed this activity, but only when the questions were humorous.
Then finally the review.