PowerPoint Macro to switch language of document to en-CA

gistfile1.vb

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
                ' List of available LanguageID values at https://msdn.microsoft.com/en-us/library/aa432635.aspx
                ActivePresentation.Slides(j).Shapes(k) _
                .TextFrame.TextRange.LanguageID = msoLanguageIDEnglishCanadian
            End If
        Next k
    Next j
End Sub

See also http://support2.microsoft.com/default.aspx?scid=kb;en-us;245468