Buy 1 Get 1 Free? or Buy 2 Get 1 Free?

冰箱空空了,晚餐只好買速食解困
經過drive thru,搖下車窗在風雪呼呼聲中,
對對講機大叫"1 blah blah combo, 1 blah blah sandwich, and i have a coupon for buy 1 sandwich get 1 free.."
開上前,他老兄在風雪中慢慢地對我說.."you have to buy 2 to get 1 free"
蛤...我瞧瞧,是買一送一沒錯呀,"it says, buy 1 get 1 free, so I'm buying ONE sandwich, and it should get me 1 for free"
"right, but...."他繼續在風雪中跟我解釋要買兩個,才有一個免費...(@#$%..老兄你不冷嘛,我都快冷死了,而且明明就是買一個送一個,你在跟我辯什麼呀...)
一陣雞同鴨講,我才猛然想到他的邏輯一定是認為[買兩個,其中一個免費]
他繼續認有必要教育我,也繼續在風雪中耐心地詢問著,"so you want to buy two?"
"Yeah, 2 sandwiches in total!"
都是"buy"這個動詞造成誤會,
免費的東西到底算不算是"買"來的呢?
雖然誤會,但還是覺得,意思表達上應該是"買一送一"
"買二,一個免費" 聽起來像是總共有三個一樣..