Dual form has been disappearing for past couple centuries. http://en.wikipedia.org/wiki/Dual_(grammatical_number) http://en.wikipedia.org/wiki/Dual_(grammatica

Dual form has been disappearing for past couple centuries. http://en.wikipedia.org/wiki/Dual_(grammatical_number) http://en.wikipedia.org/wiki/Dual_(grammatical_number) quoted // Of the living languages, only Slovene and Sorbian have preserved the dual number as a productive form. In all of the remaining languages, its influence is still found in the declension of nouns of which there are commonly only two: eyes, ears, shoulders, in certain fixed expressions, and the agreement of nouns when used with numbers.