打八折英语怎么说

打八折在英语中称作 "20% off" 或者 "20% discount"。这个说法源自商业折扣的一种方式，表示原价的 20% 会被减去，从而给客户带来更优惠的价格。

例句：

"The store is offering 20% off on all clothing items this weekend." (这家商店这个周末所有服装都打八折。)
"I got a 20% discount on my new shoes because they were on sale." (我买的新鞋子打了八折，因为它们正在促销。)
"If you apply this coupon, you'll get 20% off your purchase." (如果你用这张优惠券，你就能打八折。)