Changer la langue de tous les éléments d'un powerpoint en même temps :

Option Explicit

Public Sub ChangeSpellCheckingLanguage()
Dim j As Integer, k As Integer, scount As Integer, fcount As Integer
scount = ActivePresentation.Slides.Count
For j = 1 To scount
fcount = ActivePresentation.Slides(j).Shapes.Count
For k = 1 To fcount
If ActivePresentation.Slides(j).Shapes(k).HasTextFrame Then
ActivePresentation.Slides(j).Shapes(k) _
.TextFrame.TextRange.LanguageID = msoLanguageIDEnglishAUS
End If
Next k
Next j
End Sub