The idiomatic expression ‘the walls have ears’ means to be careful what you say as people may be eavesdropping. To eavesdrop means you secretly listen to the conversations of others.
‘the walls have ears’这一习语的意思是“小心说话，因为可能会被偷听”。“偷听”是指“偷偷听别人的谈话”。
Examples:
例如：
Be careful of what you say at work. The walls have ears.
在工作中说话要小心，因为隔墙有耳。
Stop talking! The walls have ears. Tell me when we get inside.
别说了！隔墙有耳。进屋后再告诉我。
Shhh! Walls have ears. Don’t say anything about our business dealings here.
嘘!隔墙有耳。不要在这里谈公事。
This idiom ‘‘the walls have ears’’ originates from a story about Dionysius of Syracuse in 430–367BC. Dionysius had an ear-shaped cave cut into the rock and positionedinbetween the rooms of his castle so he could hear what was being said in each room. This form of eavesdropping became common practice with rulers from many cultures. Some palaces, including the Louvre in Paris and Hastings Castle in England,were said to have such listening posts. In English, the expression was first recorded in its present structure in 1620.
“隔墙有耳”这个成语来自于公元前430 - 367年锡拉库扎（意大利西西里岛东部一港市）的狄奥尼西奥斯（Dionysius）。狄奥尼西奥斯在石头上凿了一个耳朵状的凹槽，并把这块石头置于城堡的屋子中间，这样他就能听到各个房间里的动静。这种窃听形式普遍为众多国家的统治者所沿用。据说包括巴黎的卢浮宫和英国的黑斯廷斯城堡在内的一些宫殿，都有这样的监听点。在英语中，这个表达最早出现在1620年。
There are thousands in the English language. Idioms are useful to learn if you want to get a greater understanding of the English language.
英语中有很多习语，学习这些习语有利于更好地理解英语这门语言。
重点单词和短语：
1. eavesdrop 偷听，窃听
2. position 置于；位于
3. castle 城堡
4. ruler 统治者
5. ear-shaped 耳朵形状的
6. Louvre （法）罗浮宫
7. Hastings Castle 哈斯廷斯城堡
8. listening post 监听点；情报站