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 = msoLanguageIDFrenchCanadian 
            End If 
        Next k 
    Next j 
End Sub