Well American players have proved times and again they don't put too much effort in learning the language of the country they play in.. It's obviously not shade, and there are exceptions like Logan, who speaks perfect Italian and Portuguese..
Logan does speak Portuguese indeed. She played in Brazil in early 2000s and probably learned at that time, but I think she lost it (forgot most of it) by the time she came back (in 2012). She refused to speak in Portuguese everytime she was interviewed during that season.