With a negative adverb or adverb equivalent in front position, inversion of subject and verb must occur.
当表示否定意义的副词或相当于副词的词语置于句首时，句中主谓需倒装。
2
This paper analyses the understanding and the uses of the abstract meanings of the prepositions in three parts:prepositional phrase used as a verb; the function of comparison and negative expression.