本文依据方位词“之前”单用的语言事实,运用比较的方法,从历时和共时角度对这一现象做深入剖析,在此基础上就该用法的由来及其认知基础,尤其是特有的表达功能等给出理据性解释,进而得出“之前”可以单用的结论。 Based on the dialect words “before ” single linguistic facts, this article uses the comparative method to analyze this phenomenon from the diachronic and synchronic perspectives. Based on this, the author analyzes the origin of the usage and its cognitive basis, especially Is a unique expression of functions such as justification given, and then come to “before ” can be used alone conclusions.