Options.SpanishMode (Word)
Returns or sets the mode for the Spanish speller. Possible return values are wdSpanishTuteoAndVoseo - The Spanish spelling checker recognizes both tuteo and voseo verb forms, wdSpanishTuteoOnly - The Spanish spelling checker recognizes only tuteo verb forms, wdSpanishVoseoOnly - The Spanish spelling checker recognizes only voseo verb forms.
Setting this property has the same effect as selecting an option under Spanish modes: in the Word Options dialog (Proofing, When correcting spelling in Microsoft Office programs).
Options.SpanishMode = wdSpanishTuteoAndVoseo