D.C. Code § 42-504: Freeholds; chattels real; chattel interests; conditions precedent or subsequent.

Estates of inheritance and estates for life shall continue to be denominated freeholds, and estates for years shall be chattels real; estates at will or by sufferance shall be chattel interests, but shall not be liable, as such, to sale under execution; and all estates may be subject to conditions precedent or subsequent.