'Return a sequence of adjective positions that this word can
appear in.  These are elements of ADJECTIVE_POSITIONS.
>>> ADJ[\'clear\'].getAdjectivePositions()
[None, \'predicative\']'

def getAdjectivePositions(self):

    positions = {}
    for sense in self.getSenses():
        positions[sense.position] = 1
    return positions.keys()
