What the dead lack is substance. They're so nebulous and rarified that a gas like helium seems to them as solid as a beefsteak. A child's balloon full of helium feeds a whole cemetary of ghosts for a week.
Words are money, the way time was once. Time means nothing to them now, but words... speech, hot air shaped by thought into blobs and ribbons of intelligible discourse, words have not only substance but value. Words are tangible to the dead. Legal tender. Abstract terms less tangible, lower value. The most solid language unit with the highest value as hard currency is the NOUN VERB. To the dead, nouns which do double duty as verbs are words of power. The verbs TO SNOWBALL, TO SMOKE, TO WATER, TO AIR (is human), TO FIRE are held in high regard by these kooky misfits from beyond the grave.
Orpheus notes that the word impassion is made up of three nouns.