To expand: "su" can mean "his" "her" "their" as well as the polite "your". In this context, "el marino, el hermano de su madre" risks being felt as a complete phrase in itself (the sailor, the brother of his mother), so you need "de usted" to anchor it firmly to the second person. If Juan hadn't been a sailor, (yo soy Juan de Aguirre, el hermano de su madre") then the risk wouldn't have been there but he could, as D.E. says, still have been being ultra-polite.
At 09:53 07/09/02 -0700, Doug Ewell wrote: ><Peter_Constable at sil dot org> wrote: > >>> ??Yo soy Juan de Aguirre, el marino, el hermano de su madre de usted, >> >> Can one really say, "su madre de usted"? Can you do that with any noun >> and any semantic relation expressed by the possessive construction? >> (su casa de usted, su pays de usted, etc.) > >It's an emphatic form, sort of like saying "YOUR mother" slowly while >raising one's eyebrows and pointing one's finger at the listener. (OK, >maybe not quite that emphatic.) > >I imagine you could use that form with any "possessed" noun when the >situation calls for that type of emphasis. > >-Doug Ewell > Fullerton, California > > > >
