Make a list of sentence pairs. The sentences can be either correct or incorrect (grammatically). Students get into teams. Give each team voting cards. XX means both sentences are wrong. OO means both sentences are right. XO means one is wrong and one is right. Give each group $500. Read the two sentences then ask the students for their bets. Then get the students to hold up their voting cards. Teams that are wrong lose their bets. Teams that are right win the amount that they bet. Teams can bet for bonus money if the think they can correct the sentences. The team with the most money wins. Can be played with betting minimums and maximums.