modify some url

I have on my site where the structure appear to be sections that the categories in this way:
www.mysite.com / section / categorie.html
and I would like only a few are like this:
www.mysite.com / section / categories
and in this way:
www.mysite.com / categories
how can I do?
Thank you

I don't understand. You want some of the URLs like section/category and some just category/ ?
There is no way to do this unless you want to define manual alias for each URL.

I don't understand. You want some of the URLs like section/category and some just category/ ?
There is no way to do this unless you want to define manual alias for each URL.

Hi Saka,
Sorry but I went in Alias and I put the address and no sef I put the new address sef that must end with / but he removed me and put the extension, how do I make sure that the url ends with /
Thank you

Stefano