I don't have WP installed anywhere to check, but I seem to remember an option to customise your URL structure in the control panel somewhere. If you look through the documentation then I'm sure you'll be able to work out how to do it.
Parentcat = main category
childcat = child category
Entertainment is the primary/parent category
TV is the child/sub category of Entertainment
To be honest I have given up trying to exclude the child category from the URL, the wordpress support forums never respond to any requests so I thought it easier to find a URL that would be more robust to future changes.
I don't find the WordPress.org forums particularly helpful either. There are a lot of noob coders on there and it's sometimes hard to stand out in the crowd. The phpBB.com forums seem to suffer the same fate.