As a rule, it is best to provide children with models of correct Spanish through contact with native speakers, books, audio books, video, and music. With sufficient exposure to Spanish, they will learn the structures of the language. They do not need grammar explanations.
Adults, however, often appreciate some information about grammar. The explanations on this site are very general and brief. If you are interested in learning more about Spanish grammar, there are many excellent websites with detailed explanations and practice.
Nouns, Adjectives and Agreement
In Spanish, nouns are masculine or feminine.
Most masculine nouns end in –o. If the noun is masculine, the word for “the” is el or los.
el ojo – the eye los ojos – the eyes
Most feminine nouns end in –a. If the noun is feminine, the word for “the” is la or las.
la pierna – the leg las piernas – the legs
Many adjectives change form to agree with the noun that they describe.
Most masculine nouns end in –o, so the adjective will also end in –o.
el libro amarillo – the yellow book
Most feminine nouns end in –a, so the adjective will also end in –a.
la manzana roja – the red apple
The question words cuánto/cuanto (how much) and cuántos/cuántas (how many) are adjectives that change to match the word that follows.
¿Cuántos gatos hay en el dibujo? – How many cats are there in the picture?
¿Cuántas personas hay en la familia? – How many people are there in the family?
Adjectives that end in –e don’t change to masculine or feminine.
el libro grande – the big book
la manzana grande – the big apple
Many nouns don’t end in –a or –o. It is important to learn if these nouns are masculine or feminine. You can tell by the article (el, la) in a vocabulary list. If you look the word up, the dictionary will tell you if it is masculine or feminine.
Be aware of the forms of the adjectives in these common phrases:
buenos días – good morning
(This is an exception to the rule: el día – the day. Día is a masculine noun.)