Begin by explain that the word in Spanish is formed by a LEXEME or ROOT, that is it part essential of the WORD, which brings the MEANING. And it also has a few AFFIXES ( parts NOT fixed ) that, according to the position that occupy on the LEXEME, are called: 1.PREFIJOS, when van front; 2.SUFIJOS or INTERFIJOS, when they go back. They all complete and added new semicos values to the word. EJ.lampara, porta-lamp and lampar-ill-a. In the first we see the lexeme, add a PREFIX in the second and in the latter case, the SUFFIX vun. So that they will PREFIX HUM - words that begin with such, without being part of the lexeme. But as any Word takes this PREFIX " HUM-" we say that NOT EXISTS such prefix in Spanish or Castilian. Neither human, damp, humanism, humanity or humidity and wetlands may lose such parts, because these LEXEMES.