There is one dwarf. [SINGULAR]
There are two dwarfs. [PLURAL]
There are seven dwarfs. [PLURAL]
There are one dwarf.
There is two dwarfs.
EXPLANATION here. (See #9)
Snow-White and the Seven Dwarfs
A Tale from the Brothers Grimm
Written by Jacob and Wilhelm Grimm; Pictures by Nancy Ekholm Burkert; Translated by Randall Jarrell