GNOME and Ubuntu usability issues

... but you shouldn't find "shutdown" as a verb. The full term would be "shut the system down" or "shut down the system". You want to label the activity, not the noun phrase for the activity.

"Username" and "reboot" are techno-babble, from the point of view of somebody who doesn't care about computers but just wants to work with 'em. That's what Matthew was talking about. (Also, it would have to be user name, not username, if you want to use this nomenclature at all, rather than "your name" or the like.)