Database Software

Hi all,

I'm using Oracle 11g DB.
I need to create a full-text search application, using stemming function and thesaurus.

I am able to compose the stemming opertor ($) and the synonymus operator (SYN) in my query, so that i can search all documents that contain the stem of all the words returned by SYN ( CONTAINS($SYN(myword, mythesaurus)) ). That works perfecly.

The problem is when the word i use in my query is not in the base form. For example, if i use the plural of the word, the SYN operator does not return any related word contained in my thesaurus.
Does anyone know if there is a way so that i can retrieve the base form of the search word, so that i can use the base form of the word in the SYN operator?

EG.
when the user enter the word "spoken" in the application form, before querying the documents, i want to manipulate the query, retrieving the base form of the search word "spoken", and use the base for inside the SYN operator.

Any help will be appreciated. i just need to know if there is a way, any solution can be useful for me. is there a way to customize the SYN operator, or a way to query the thesaurus?

Regards
Alessandro