在英語中，如果你想教人砍價，你可以使用以下一些表達方式：
1. "How much can I bargain this?"
2. "Can you give me a discount?"
3. "I'm willing to pay a certain price, but I'm willing to bargain for a better deal."
4. "I'm not happy with the price, can you negotiate?"
5. "I'm looking for a better price, do you have any room for negotiation?"
6. "I'm not happy with the price, can you lower it?"
7. "Can we discuss the price?"
8. "I'm willing to pay a reasonable price, but I don't want to overpay."
記住，砍價是一種交流技巧，也是建立信任和尊重的過程。你應該以禮貌和尊重的方式與賣家交流，同時堅持你的立場和要求。