Nouns of locality indicate direction and location. There are two kinds of them: the monosyllabic ones, like shàng, xià, lǐ, etc. and the disyllabic ones, like shàngmian (bian), xiàmian (bian), lǐmian (bian), etc. When the nouns of locality are followed by nouns, “de” is often omitted.
方位词是表示方向或位置的词。方位词有单音节的，如：上、下、里等等，也有双音节的，如上面（边）、下面（边）、里面（边）等等。方位词用于名词后面时，“的”一般省略。
Nouns of locality are used with “yǒu” or “zài” in a sentence to indicate the existence of someone or something in a particular place.
方位词一般和“有”或“在”同时出现在句子中表示存在。
1. “yǒu” is used to indicate the existence of someone or something in a particular place.
“有”表示某处存在某人或某物。
2. “zài” is used to indicate the location or position of something.
“在”表示某事物的方位和处所。
3. When we know there is someone or something in a particular place but we want to know more specifically who is or what it is, we use “shì”.
当知道某处有某人或某物时，要求确指某人是谁、某物是什么时，我们用“是”。
