Q: What’s purple and commutes?
An Abelian grape.
Q: What is purple and all of its offspring have been committed to institutions?
A simple grape, it has no normal subgrapes.
Q: What is lavender and commutes?
An Abelian semigrape.
Q: What’s purple, commutes, and is worshipped by a limited number of people?
A finitely-venerated Abelian grape.
Q: What’s purple, round, and doesn’t get much for Christmas?
A finitely presented grape.