Set proofing language for all text in presentation at once

[judithvg]

Can I change the proofing language for all the text in a PowerPoint presentation at once?
My experience is that it has to be done slide by slide (Control All - Set Proofing Language), but it seems quite improbable that this is still the case in the latest versions of PowerPoint.
Up to PPT2007 the slide by slide language setting could be done quite fast by using F4 (to repeat your last action), but that doesn't seem to work anymore in PPT2010, or at least not for that particular action.
Also, even when using Control All, any table text does not get included so all tables have to be 'language set' separately by selecting the text within the table.


Changing the language in the master slide text holders doesn't work either.
Hope that I have been overlooking a PPT function, may thanks in advance for your help!