语言是人类所特有的用来表达思想、交流思想的工具，而具体的文字形式与所表达的语言之间并非总是对应的关系。在语言交际中，由于文化水平，职业差异、社会地位，文化修养等多种原因，人们完全可以用不同的词语表达相同的意思。反之，人们也完全有可能用同一词句表达不同的 Language is a unique instrument used by human beings to express ideas and exchange ideas. However, the relationship between the specific written form and the expressed language is not always corresponding. In language communication, people can express the same meaning in different words due to different reasons, such as their cultural level, occupation differences, social status and cultural accomplishment. Conversely, it is entirely possible for people to express different words in the same sentence