Sub findMm()
Dim oRng As Range
Dim strfind() As Variant
Dim strreplace() As Variant
Dim i As Integer
    strfind = Array("A", "An", "The", "To", "With")
    strreplace = Array("a", "an", "the", "to", "with")
    For i = 0 To UBound(strfind)
        Set oRng = ActiveDocument.Range
        With oRng.Find
            .ClearFormatting
            .Replacement.ClearFormatting
            .Text = strfind(i)
            .Format = True
            .Forward = True
            .MatchWildcards = False
            .MatchCase = True
            .MatchWholeWord = True
            Do While .Execute
                If Not oRng.Start = oRng.Sentences(1).Start Then
                    oRng.Text = strreplace(i)
                End If
                oRng.Collapse 0
            Loop
        End With
    Next i
    Set oRng = Nothing
End Sub