Word formation: diminutives, augmentatives, prefixes and -mente

What it is

Spanish builds new words with suffixes and prefixes, and some of them change more than the dictionary meaning. Appreciative suffixes (sufijos apreciativos) add size, affection, politeness, irony or contempt: casa → casita (a little or cosy house), casona (a big old house), casucha (a hovel). Prefixes build opposites, repetitions and degrees: posible → imposible, hacer → deshacer, leer → releer, fácil → superfácil. And -mente turns adjectives into adverbs: rápido → rápidamente.

In Latin America diminutives are everywhere, and they rarely just describe small things: un cafecito, un momentito, ahorita, cerquita. Using them well is part of sounding warm and natural.

How to form it

Diminutives. The default is -ito / -ita, which replaces a final -o or -a: perro → perrito, mesa → mesita. The final vowel of the base stays, whatever the gender: el problema → el problemita, el mapa → el mapita, la foto → la fotito. Words ending in -e, -n, -r or a stressed vowel take -cito, and one-syllable words take -ecito:

Spelling adjusts to keep the sound: poco → poquito, amigo → amiguito, agua → agüita, taza → tacita. The written accent of the base disappears, because the stress moves to -ito: café → cafecito, árbol → arbolito, camión → camioncito. In Latin America short words often take plain -cito (pancito, florcita, trencito).

There are regional variants: -ico in Costa Rica, Colombia, Venezuela and Cuba, mostly after a t (un momentico, chiquitico), and -illo, frequent in Spain and frozen in many everyday words (tortilla, ventanilla, bolsillo).

Augmentatives and pejoratives. -ón / -ona means big or a lot (un problemón, una casona); it can turn a feminine noun masculine (la noticia → un notición). Added to verbs, it describes a habit (llorón, dormilón, preguntón) or a sudden movement (empujón, apretón). -azo means "big and impressive" (golazo, partidazo, exitazo) or a blow with something (portazo, codazo, cabezazo). -ucho and -ejo are openly negative: un pueblucho, un cuartucho, un animalejo.

Prefixes.

In- becomes im- before p and b (imposible, imborrable) and i- before l and r, with the r doubled (ilegal, irreal, irresponsable). Before m and n it stays: inmaduro, innecesario. Prefixes are written together with the word, without a hyphen: exnovio, superrápido (double r again), antiinflamatorio.

Adverbs in -mente. Add -mente to the feminine singular: rápida → rápidamente, tranquila → tranquilamente. One-form adjectives just add it: fácil → fácilmente, amable → amablemente. A written accent stays where it was: rápidamente, fácilmente, últimamente. In a series, only the last adverb keeps -mente; the others stay as feminine adjectives: rápida y fácilmente, clara y directamente.

When to use it

• Affection: mi abuelita, mi perrito, mi amorcito.
• Politeness: a diminutive softens a request or an offer: ¿Me esperas un momentito?, ¿Te sirvo un cafecito?, Firme aquí abajito, por favor.
• Playing things down: Es solo un problemita. Tengo una gripita.
• Intensity, with adjectives and adverbs: cerquita (really close), tempranito (nice and early), despacito (nice and slowly), igualito (exactly the same), solito (all alone). Ahorita means "right now" or "in a bit" in Mexico, but "later" in much of the Caribbean.
• Judgement: -azo praises (¡Qué golazo!); -ucho and -ejo sneer.
• -mente suits careful speech and writing. In conversation people often use the adjective itself as an adverb (maneja rápido, habla bonito) or say de forma / de manera + adjective.

• Mi abuelita vive solita en una casita cerca del mar.My grandma lives all by herself in a little house near the sea.affection, intensity, size
• ¿Te sirvo un cafecito mientras esperas?Can I get you a coffee while you wait?politeness
• Dio un portazo y se fue sin despedirse.She slammed the door and left without saying goodbye.-azo = a blow
• Lo resolvimos rápida y fácilmente.We solved it quickly and easily.-mente in a series

Contrasts and traps

• Don't read diminutives literally. Un cafecito is a friendly coffee, not a small one, and ahorita is not "a little now".
• Frozen words have their own meaning: bolsillo (pocket), ventanilla (ticket window), sillón (armchair), cajón (drawer), flechazo (love at first sight).
• -ito or -cito? ✗ cafeito, ✗ camionito → cafecito, camioncito; and ✗ problemito → problemita.
• Spelling of in-: ✗ inposible, ✗ inlegal → imposible, ilegal.
• -mente in a series: rápidamente y fácilmente is possible but heavy; ✗ rápido y fácilmente is wrong: rápida y fácilmente.
• Register: -azo, -ucho and super- are colloquial. In a formal email write muy fácil, not superfácil.

If you speak Portuguese

Your -inho / -zinho maps onto -ito / -cito: cafezinho → cafecito, pouquinho → poquito, pertinho → cerquita. Watch two spelling traps: Spanish keeps the accent before -mente (rápidamente, not ✗ rapidamente) and writes inm- where Portuguese has im- (inmaduro, inmóvil). Portuguese desnecessário is innecesario.