Techniques for determining when and how to transform words in a query to its plural or non-plural form in order to provide the most relevant search results while minimizing computational overhead are provided. A dictionary is generated based upon the words used in a specified number of previous most frequent search queries and comprises lists of transformations from plural to singular and singular to plural. Unnecessary transformations are removed from the dictionary based upon language modeling. The word to transform is determined by finding the last non-stop re-writable word of the query. The context of the transformed word is confirmed in the search documents and a version of the query is executed using both the original form of the word and the transformation of the word.