满100元减20元，用英文怎么说？

哈，我的这个是很标准的折扣用语哦~

buy 100 Yuan get 20 Yuan reduction

Twenty yuan will be deducted if the total sum reaches one hundred.

满100元减20元
You will get twenty off when it's one hundred.

You will receive 20 RMB cash back when your purchased 100 RMB

20 RMB OFF UPON 100 YUAN COMSUPTION