The most commonly spoken language among the developers and BugSquad is English (or so it seems). Its therefore useful to get english error messages on bug reports.
Translating the bug report
use http://translate.google.com/ to translate the bug report
ask in #ubuntu-bugs if somebody speaks the language in question
- ask the reporter politely if they can reply in English
If a user has posted a non-english error, politely ask them to run the command preceded by
LANGUAGE=C sudo apt-get upgrade