I check a lot of large documents and it is amazing how many people still don't put full stops at the end of a sentence.
Are you saying these large documents are ONE paragraph, in that by full stop you mean a paragraph mark? They are using a Shift-Enter to make a new line (but the same paragraph)?

If so, then by definition you can not have a maco searching for "the end of a paragraph", because without a "full stop" (paragraph mark), there is no end of the paragraph.

Please clarify.

Have you tried recording such a macro? To replace line breaks, with paragraph marks, it wouldf be something like:[vba] Selection.Find.ClearFormatting
Selection.Find.Replacement.ClearFormatting
With Selection.Find
.Text = "^l"
.Replacement.Text = "^p"
.Forward = True
.Wrap = wdFindContinue

End With
Selection.Find.Execute Replace:=wdReplaceAll[/vba]