In languages with Gender distinctions in the Singular, the existence of a Gender distinction in 1st and /or 2nd person non-Singular implies the existence of the same Gender distinction in the Singular involving either the corresponding person(s) or 3d person.
Standardized
When there are gender distinctions in the singular, IF there is a gender distinction in 1st and/or 2nd person non-singular, THEN there is the same gender distinction in the singular involving either the corresponding person(s) or 3rd person.
This is a corrected version of Greenberg’s Universal 45 (see #520). See further Plank & Schellinger 1997.