Amanda Knox: Taking the Stand, Will Testify in Italian

Deciding to forgo her translater:  Accused murder accomplice,  Univeristy of Washington student Amanda Knox will take the stand in Perugia,  Italy in  early June,  speaking in Italian.  Her attorney has said she has good command of the language,  and a "good accent".   I am surprised at this, because certainly one has better command over the primary language.  Is this part of the "once removed"  technique?  Or simply a display of her competence and self-composure?  Will be interesting to see and hear such testimony,  after all of this speculation.