Google - search for a particular word, a sub-menu appears, how this happens?

I was doing some tests on Google, and I noticed a thing.

When I search for a particular word, the first on the list, appears as a sub-menu.

Word typed: Jornal destak

http://img210.imageshack.us/my.php?image=googlesubmenuob6.jpg

My question:
How can I do that?
Why this not happens with every word?

Sorry about my English.