Identify nouns that are masculine or feminine masculine nouns generally end in o; feminine nouns end in a nouns generally end in a.
Spanish and other romantic languages have gender which is determined by the articles el libro, la casa, el suelo, la television: non living nouns have arbitrary articles, there is no definition for masculine or feminine noun.
Gender of Nouns_Spanish-Part 1
Cardinal numbers in Spanish from 0-10
The idea that nouns have gender seems perfectly natural when the noun stands for a living creature. This is because in English, living creatures often have different names, depending upon whether they are male or female.