Q:

How to install Gnome2 on Xubuntu?

How to install Gnome2 on xubuntu 11.04 ? 

A:

The easiest way to use gnome in xubuntu is to just install Ubuntu in the first place, but if you must installing gnome via apt-get should work, but it might give you a ton of extra packages.
sudo apt-get install gnome

or better yet the ubuntu desktop
sudo apt-get install ubuntu-desktop

