code: private static String mapGalicianCTAGTagSetToNAF(final String postag) {
      if (postag.startsWith("R")) {
        return "A"; // adverb
      } else if (postag.equalsIgnoreCase("CC") || postag.equalsIgnoreCase("CS")) {
        return "C"; // conjunction
      } else if (postag.startsWith("D") || postag.startsWith("G")
          || postag.startsWith("X") || postag.startsWith("Q")
          || postag.startsWith("T") || postag.startsWith("I")
          || postag.startsWith("M")) {
        return "D"; // det predeterminer
      } else if (postag.startsWith("A")) {
        return "G"; // adjective
      } else if (postag.startsWith("NC")) {
        return "N"; // common noun
      } else if (postag.startsWith("NP")) {
        return "R"; // proper noun
      } else if (postag.startsWith("S")) {
        return "P"; // preposition9434233199310741
      } else if (postag.startsWith("P")) {
        return "Q"; // pronoun
      } else if (postag.startsWith("V")) {
        return "V"; // verb
      } else {
        return "O"; // other
      }
    }
docs: Mapping between CTAG tagset and NAF.
  
  @param postag
  the postag
  @return the mapping to NAF pos tagset