Natural Gender is distinction as to the sex of the object denoted: as, puer (M.), boy; puella (F.), girl; rēx (M.), king; rēgīna (F.), queen. Many nouns have both a masculine and a feminine form to distinguish sex : as, cervus , cerva , stag , doe; cliēns , clienta , client; victor , victrīx , conqueror.

Many designations of persons (as nauta , sailor ) usually though not necessarily male are always treated as masculine. Similarly names of tribes and peoples are masculine: as, Rōmānī , the Romans; Persae , the Persians. A few neuter nouns are used to designate persons as belonging to a class: as, mancipium your slave (your chattel).

Many petenames of girls and boys are neuter in form: as, Paegnium , Glycerium . Names or classes or collections of persons may be of any gender: as, exercitus (M.), aciēs (F.), and agmen (N.), army; operae (F. plur.), workmen; cōpiae (F. plur.), troops; senātus (M.), senate; cohors (F.), cohort; concilium (N.), council.