Sub GermanTextBoxFinder()
    Dim SlideToCheck As Slide
    Dim ShapeIndex As Integer
      ' Visit each slide
    For Each SlideToCheck In ActivePresentation.Slides
      ' On each slide, count down through the shapes
    For ShapeIndex = SlideToCheck.Shapes.Count To 1 Step -1
      ' If the shape IS a text box and DOES have German text
    If SlideToCheck.Shapes(ShapeIndex).Type = msoTextBox And _
    MsoLanguageID.msoLanguageIDGerman _
Then
    ' Toggle visibility of German Textboxes
    SlideToCheck.Shapes(ShapeIndex).Visible = msoFalse
End If
Next
Next

End Sub

If SlideToCheck.Shapes(ShapeIndex).Type = msoTextBox And _
    Left(SlideToCheck.Shapes(ShapeIndex).Name, 6) = "txtGER" Then
    ' Toggle visibility of German Textboxes
    SlideToCheck.Shapes(ShapeIndex).Visible = msoFalse
Else
    SlideToCheck.Shapes(ShapeIndex).Visible = msoTrue
End If