static Triple<S> ai_tripelize(S s) {
  L<S> tok = nlTok(s);
  S a = get(tok, 1);
  if (a == null) null;
  if (ai_questionWord_1(a)) { tok = subList(tok, 2); a = get(tok, 1); }
  if (ai_yesNoQuestionWord_1(a) && neqicOneOf(a, "am", "are", "is")) {
    L<S> tok2 = subList(tok, 2);
    int i = indexOfFirstVerb(tok2);
    S v = get(tok2, i);
    if (v != null)
      if (eqic(a, "does")) ret verbToThirdPerson(v) + "?";
      else if (eqic(a, "do")) ret v + "?";
      else if (eqic(a, "did")) ret verbToPast(v) + "?";
      else ret a + " " + v + "?";
  }
  if (isVerb(a))
    ret triple(
      "",
      a + "?",
      "");
  
  int i = ai_endOfNounPhrase(tok);
  int j = indexOfFirstVerb(tok2, i);
  ret triple(
    trimJoinSubList(tok, 0, j),
    tok.get(j),
    trimJoinSubList(tok, j+2));
}