When the overseas students who study in Chinese learning programs, they often make mistakes like以后他结婚就出国了, which is usually cased by the misunderstanding on the nouns of location. The most frequently seen nouns of locality are 上、下、前边and后边. As a matter of fact, the nouns of locality can be divided into two types, the basic direction word and the compound direction word.

The words of the former classification include 上, 下, 前, 后, 里, 外, 内, 中, 左, 右, 东, 西, 南and 北. And the compound direction words are composed of the simple direction words and the structures like 边（儿）, 面（儿），头（儿），之and以 such as 上边, 下面, 中间, 之内and 以下.

Generally speaking, except for 左and右, the basic direction words are placed after the nouns such as 窗户上and椅子下. One point that the foreign students who study Mandarin Chinese need to know is that such kind of words do not function as subject and object alone. That is why it is hard for the students to learn. Only in the symmetrical format or after the prepositions of direction 往, 向and从 can they function as the subject or object.

For the compound direction words, the application seems more flexible. It can not only be placed after the nouns such as 桌子上边and同学之间, but also be the attribute of the nouns like 上边的桌子and外边的车子. In addition, they can also act as subject and object alone. For instance, 里面有人.

What’s more, the foreign students who study in qualified Mandarin program should know when the nouns of locality and nouns combined together to indicate the location, the word order should be “noun + (的) + nouns of locality”. However, the overseas students often transpose the order and speak sentences like 以后他结婚就出国了. The mistakes are often made especially when using the words以前and以后.