Every noun is either masculine or feminine, so it really is a question of learning new words with the "el" or the "la"..... Then, depending on the gender of the noun, you make adjectives agree, such as "LA casa bonitA" or "EL coche bonitO" There are some adjectives that need no agreement, such as "blue", "azul".

formation of the masculine 1 nouns ending in o are masculine: el libro (the book); el banco(the bank) exception: la mano 8the hand) la radio (the hand) 2most nouns in l or r and nouns of Greeg origin ending in ma el papel, el azucar el favor, la miel. 3 days of the week,moths, rivers and mountains: el martes formation of the feminine nouns ending in o change to a tio (uncle) tia (aunt) niñi (boy) niña (girl) nouns ending in on or add- a pastor -pastora; patron- patrona