have you tried just searching the community?
You can also remove prepositions with the Filter Stopwords operator from the free Text Processing extension (available in the RapidMiner Marketplace).
I am afraid that your question is too generic for anyone to know how to help. Have you tried looking through the Rosette website for their tutorials, such as this one: https://www.rosette.com/blog/once-more-with-feeling-pats-nation/
Maybe if you have an actual process you can post with a more specific question, it would be easier for the community to help you.
HelloYou are rightI visited the site, but I did not understandPlease, magnify and guide me?Many thanks to dear professor
@ahootanha I would visit the KB articles posted about Rosette here or visit their website. I don't have a lot of experience with their tools.