Give each team a piece of paper and write the first sentence on the whiteboard/blackboard. Here are a few examples (remembering to omit the correct/incorrect part):
Correct: I want to buy a new computer.
Incorrect: Yesterday I will go to the library.
Correct: I love playing basketball after school.
Incorrect: You're photo is beautiful.
Give them around a minute to discuss the sentence in their groups before asking them to make their bets on the piece of paper you gave them. Let the students know that if they're unsure about a sentence then they should probably bet less money.
It's also a good idea to make the maximum bet half of what they currently have so they can't lose all their money. For example, if you gave each team $10000 then the maximum bet would be $5000.
A typical bet might look like this:
Correct sentence: $5000
Incorrect sentence: $3000
Collect the pieces of paper and hand out the winnings/collect the losses equal to how much they bet. Play as many rounds as you like, get each team to count their winnings at the end and see which team finishes with the most money. You might like to keep track of this on the whiteboard/blackboard as the game progresses.