Sentence Auction: the whiteboard game that makes grammar mistakes worth actual money

You write ten sentences on the board. Seven are clean, three are wrong. Each team gets ₩10,000 in play money—torn paper, tally marks, whatever. They bid on sentences they think are correct. Highest bid wins that sentence. At the end you reveal which were good. The team holding the most correct sentences wins, even if they spent everything.

The game works because students have to commit with limited money. They can't bid on everything. That forces discussion: is "He go to school yesterday" wrong, or does it sound wrong but we're missing something? A team that bids ₩4,000 on a broken sentence and wins it has just bought themselves a loss, which lands harder than you marking it wrong on paper.

How to set it up

Write your sentences before class. For a 40-minute slot, ten sentences is about right—any more and the bidding drags. Mix obvious errors with subtle ones. At least two sentences should look wrong but be correct, because overconfidence is half of what you're teaching.

Give each team the same starting amount. We've used ₩10,000 because it's easy to split into bids, but you could do $100 or 10,000 points. What matters is that they can't buy every sentence even if they wanted to.

Run the auction one sentence at a time. Read it aloud, give them thirty seconds to confer, then take bids. If no one bids, the sentence goes unsold—which sometimes happens when everyone thinks it's wrong. That's fine. Write the winning team's name next to the sentence and move on.

What to put on the board

The best sentences are the ones where half the class is sure it's right and half is sure it's broken. "I've been to Seoul" vs "I've gone to Seoul" will split a room of Korean teenagers because their textbook has drilled been but their YouTubers all say gone. Let them bid it out.

Throw in one sentence that looks wrong but follows a rule they learned two units ago. "Never have I seen such a mess" will get argued over because of the inversion, but it's correct and someone will remember. When they win that sentence for ₩500 because no one else bid, they've just made a smart trade.

Three ways it goes sideways and the fix

Teams run out of money halfway through. That's the game. If they blew ₩8,000 on the first three sentences, they sit out the rest and learn to budget next time. Do not give them more money.

A team bids everything on one sentence. Let them. If it's correct, they win. If it's "He don't like apples" and they just spent ₩10,000 on it, the room will remember that longer than any worksheet.

You wrote a sentence wrong by accident. Has happened. If you wrote "She go to school" intending it to be correct, and the room calls you on it, admit it and pull the sentence. Do not try to defend it. They'll trust the next game more if you're honest when you screw one up.

Scaling it

For elementary, use six sentences and cut the play money in half so the math is easier. Stick to present simple errors and missing articles. "I go to park" will get bids.

For high schoolers, write twelve sentences and include two that are controversial—split infinitives, singular they, starting with and. The argument over whether "To boldly go" is correct English is worth more than the game. Let it run a few minutes, then tell them descriptivists would buy it and prescriptivists wouldn't, and move on.

You can theme the sentences to whatever grammar you've been teaching, but it works better if you mix in older stuff. A board of only past continuous makes the game too easy. Throw in a rogue article error or a subject-verb slip from three months ago.

The week after you run this the first time, at least one student will ask if you're doing it again. That's when you know it worked.