Noun gender
English nouns don't have grammatical gender — a 'house' is just a 'house'. Spanish nouns always carry gender (masculine or feminine), and that gender drives the article (el/la) and adjective endings. Good news: the last letter of the word is usually a clue.
The -o / -a rule
Words ending in -o are almost always masculine: el libro (book), el gato, el médico, el dinero. Words ending in -a are almost always feminine: la casa, la mesa, la planta, la amiga. This covers most nouns you'll meet in your first weeks.
Other endings (consonants and -e)
Less predictable — learn the gender along with the word. Often masculine: el pan, el café, el coche (car), el hombre (man). Often feminine: la noche (night), la luz (light), la ciudad (city). Tip: don't memorize pan, memorize el pan — the article becomes part of the word.
Sneaky exceptions
el día (day) — masculine despite ending in -a. el mapa (map), el problema (problem), el sistema, el idioma — all masculine, all from Greek. la mano (hand) — feminine despite ending in -o. la foto, la moto — short for la fotografía, la motocicleta — that's why they're feminine.
Adjectives agree with nouns
Adjectives change endings to match: bonito → bonita. el gato bonito (pretty cat) but la casa bonita (pretty house). Adjectives ending in -e or a consonant don't change for gender: el chico amable / la chica amable. Plural adds -s: gatos bonitos, casas bonitas.
People and animals
For people and paired animals there are two forms: el amigo / la amiga, el chico / la chica (boy/girl), el profesor / la profesora, el perro / la perra. If the gender is unknown or mixed, default to masculine: los amigos = the friends (not necessarily all male).
