If the word ends in an "a" then it is feminine. If it ends in an "o" then it is masculine.
EX:
disordenad(a) - feminine
disordenad(o) - masculine
To make an inanimate object masculine, the person you're describing has to be a boy. To make the object feminine, the person you're describing has to be a girl. Same with personality.
EX:
Ella es disordenada.
El es disordenado.
Some words don't have a masculine or feminine form. if a word ends with an "e" than that means it doesn't have a masculine or feminine form.
EX: Inteligente. It doesn't end in an "o" or "a" therefore, it is can be used as either masculine or feminine.
EX:
El es inteligente.
Ella es inteligente.
