用英語學英語：怎麼理解on the house是「免費」的意思？
英語難學嗎？一點不難學，前提條件是：只要你肯勤快動手查查字典，確切的說是「英英字典」，而不是「百度」之類的英漢字典。
1) 相信很多學過英語口語表達：It's on me=I'll pay for you=I'll foot the bill的人都知道這裡的
on有pay the money的意思，類似中文「包在。。。身上」的「上」字。
2) 相信很多學過英語口語表達：The house always wins(玩不過莊家的，莊總是贏家，買的沒有賣的精)。你就會知道這裡的the house=the management=the establishment
有了這兩句對on和house理解的「墊底」，on the house中對on和house的意思就不難理解了(但是，估計看短語on the house還是不排除有其「本義」「在房頂上」的含義的，要看出現的上下文)。
3) 我們還是「問問」英英字典吧，Put English into English
on the house：
1. as a gift from the management, free
2. Paid for by the merchant or the establishment or the management
3.[of something] given away free by a merchant
4. At the expense of the establishment
5. (of drinks or a meal in a bar or restaurant) free(of charge)
正是因為我們Put English into English，用英語學英語，我們才可以把學過的英語as a gift from the management啦, free啦，Paid for by the merchant or the establishment or the management啦， given away free 啦，At the expense啦(多漂亮的短語！) ，free(of charge)啦「用」起來，同時用它們表達on the house
4) Put English into English英語口語訓練
1. Okay.Got you.Just like：It's on me and The house always wins, On means Paid by,House means the management
2. So,On the house means your food or drinks are paid for by,at the expense of the management.It means It's free!
For example,you may say：
4. Tonight the drinks are on the house.
5. Please accept this bottle of wine on the house as an apology.
6. Don't worry, this round is on the house.
7. I went to a restaurant last night. I was the ten thousandth customer, so my dinner was
on the house.
當你的英語學習終於能做到「見英語，想到的還是英語」，而不是望文生義的中文時，你不僅學會是在「學」幾句實用英語口語，更重要的是你的英語正在踏踏實實的進步。