As you know, most nouns ending in -o are masculine and most ending in -a are feminine. The exceptions can be particularly unexpected when they are names. It is a good idea to become familiar with the common exceptions to avoid confusion and embarrassment.
|Women’s names ending in -o>||Men’s names ending in -a|
|Rocío, Rosario, Consuelo||Chava, José María|
Some names are used for both men and women:
|Women’s names||Men’s names|
|Guadalupe (Lupe)||José Guadalupe|