iworklanguagenumbers
I would like to set the default language of a Numbers document. I figured out how to do it for a Pages document:
How Do I Set the Default Language in Pages?
but I cannot find the corresponding inspector tab in Numbers.
How can I set the default language of the Numbers document to e.g. German? The OS and other programs should remain in English, however.
To follow up Martin's answer, for British English you will need to edit the list and check the "British English" tick box. I spent while looking for "English (British)", but it's the former format that appears.
Right click on the song (you can select more than one), select "Get Info", choose the Options tab, and pick English for the voice over language.
If you don't see this in your info panel it means that the VoiceOver Kit is not installed: Follow the instructions on this KB Article to download and install it.
However those instructions do work on the Shuffle and the 5th generation Nano, but I just tried my daugther's 6th generation Nano and the check box is not there. Sorry.
Best Answer
According to what you've done in Pages, I assume that you want to change the language of the document cells in numbers. What you did in Pages changed the language of the document, not the application.
Changing the language of document cells
Edit > Spelling > Spelling...
Changing the language of the applications
This is not possible from within pages. As of iWork '09 the used language follows the set language defined under System Preferences → Language & Text.
However, you can start applications in a custom language via Language Switcher (works in Lion). But even with this tool you cannot set the language in which an applications starts permanently. You have to start it via Language Switcher every time.