Plural nouns and adjectives
English plurals can get strange — mouse becomes mice, foot becomes feet. Spanish hands you two endings and almost no surprises: -s after a vowel, -es after a consonant. Then everything holding on to the noun goes plural with it, the article and every adjective included: la flor bonita → las flores bonitas.
Ends in a vowel → add -s
casa → casas, gato → gatos, amigo → amigos, libro → libros, mesa → mesas, fruta → frutas. The articles do exactly the same thing: el → los, la → las, un → unos, una → unas. Put them together and the whole phrase moves at once: el gato → los gatos, una fruta → unas frutas, la mesa → las mesas.
Ends in a consonant → add -es
pan → panes, flor → flores, señor → señores, ciudad → ciudades, reloj → relojes (watches), papel → papeles (papers). The 'e' is there for your mouth: Spanish will not end a word in -rs or -ds, so it slips a syllable in. A word ending in a stressed -í or -ú behaves like a consonant word and takes -es too: el colibrí → los colibríes, el bambú → los bambúes.
Spelling shifts: -z becomes -ces
Before the plural ending, a final 'z' is written 'c': lápiz → lápices, luz → luces (lights), el pez → los peces (fish). Nothing changes in the mouth — seseo is the standard from Tijuana to Ushuaia, so the 'c' in lápices is the same plain /s/ as the 'z' in lápiz. Written accents shuffle for the same silent reason: canción → canciones and avión → aviones drop their accent, while joven → jóvenes and examen → exámenes grow one. The stressed syllable never moved; only the rule about when to draw the mark did.
The article and the adjectives go plural too
Make the noun plural and its whole entourage follows: la flor bonita → las flores bonitas, un mercado lleno → unos mercados llenos. Adjectives run on the same two rules — vowel → -s (bonito → bonitos, pequeña → pequeñas, viejo → viejos), consonant → -es (joven → jóvenes). Adjectives already ending in -e simply add -s: amable → amables, grande → grandes. One masculine member makes the whole group masculine: a boy with three girls is los chicos. And when you address more than one person, that is ustedes — the one plural 'you' in Latin America, closest friends included — with everything around it plural: Ustedes son muy amables.
Words that mean many but count as one
la gente means people, and Spanish files it as a singular: La gente es amable., La gente compra frutas. — never las gentes son. When you need to count heads, switch to las personas, which is an ordinary plural: unas personas. la fruta has the same double life: Vendo fruta. covers the whole stall as one category, while las frutas points at the different kinds sitting on it.
