, are preceded by the masculine el to avoid the ackward sound of la ... a.
If a noun ends in -ie, -ad, and -ud is always feminine.
La verdad/the truth.
La plenitud/the fullness.
La serie/the serie.
Nouns ending in -ción , -sión and -umbre are always feminine.
La ilusión/the illusion.
La cumbre/the peak.
La misión/the mission .
Are feminine the letters of the alphabet and sicknesses.
La eme (m).
La fiebre/the fever.
Nouns to persons and animals can be masculine or feminine.
El padre/the father.
La madre/the mother.
Usually, in Spanish nouns referring to a person's profession do not change according to gender.
El cantante (male), la cantante (female) - cantante/singer.
Many Spanish students make mistakes with words ending in -ma. Some of that names are masculine.
El problema/the problem.
El tema/the subject.
There are some rules to form the plural of nouns depending on the ending of the noun: