Mark Duplicated Words

If you'd like an easy way to improve your writing style, try this lengthy-looking macro and function.
It examines each sentence in your document looking for repeated words.
A string "strDismiss" is set up to avoid reporting words which I think are allowed to be repeated.
repeated words are flagged with Microsoft Word's character style "Strong", so you may want to modify that in your Normal.dot to be bright pink, 16 point, or whatever.
Don't forget that you can clear all local formatting with Ctrl-A followed by Ctrl-Space.

Public strDismiss As String

Sub MarkDuplicatedWords()

    strDismiss = vbTab & "for" & vbTab & "and" & vbTab & "that" & vbTab & "," & vbTab & "." & vbTab & "to" & vbTab

    strDismiss = strDismiss & "http" & vbTab & "://" & vbTab & "www" & vbTab & "com" & vbTab & "/" & vbTab & "the" & vbTab

    strDismiss = strDismiss & "a" & vbTab & "of" & vbTab & "www" & vbTab & "com" & vbTab & "/" & vbTab & "the" & vbTab

    strDismiss = strDismiss & """" & vbTab & "of" & vbTab & "www" & vbTab & "com" & vbTab & "/" & vbTab & "the" & vbTab

    Dim prg As Paragraph

    For Each prg In ActiveDocument.Paragraphs

        Dim snt As Range

        For Each snt In prg.Range.Sentences

            If lngCountDuplicatedWords(snt, strDismiss, ActiveDocument.Styles("Strong")) > 0 Then

            Else

            End If

        Next snt

    Next prg

End Sub

Function lngCountDuplicatedWords(rng As Range, strDismiss As String, sty As Style)

    Dim lngResult As Long

    Dim strSentence As String

    strSentence = vbTab

    Dim wd As Range

    For Each wd In rng.Words

        Dim strWord As String

        strWord = Trim(wd.Text)

        If InStr(1, strDismiss, vbTab & strWord & vbTab) > 0 Then ' we can ignore this word

        Else

            If InStr(1, strSentence, vbTab & strWord & vbTab) > 0 Then

                lngResult = lngResult + 1

                wd.Style = sty

            Else

                strSentence = strSentence & strWord & vbTab

            End If

        End If

    Next wd

    lngCountDuplicatedWords = lngResult

End Function