The Spanish words you already know (and the rules behind them)

If you speak English, you already recognize a good chunk of Spanish. When we compared the 2,000 most common words of spoken English with Spanish, 643 of them had a Spanish twin: a word with the same Latin root that you can understand just by looking at it. These are cognates, and reading the pairs from the other side gives you hundreds of Spanish words you never had to learn.

This article explains where that number comes from, the rules that turn one word into the other, and real examples of each rule.

Where the number 643 comes from

The count was made on our list of the 2,000 most used English words, built from film and TV subtitles. Each word was compared with Spanish and placed in one of three groups:

• 79 identical: same spelling, ignoring accents. Hospital, hotel, idea, chocolate.
• 142 by rule: they follow a fixed pattern at the end of the word. Station and estación, really and realmente.
• 422 similar: no rule, but easy to recognize. Person and persona, problem and problema.

That adds up to 79 + 142 + 422 = 643. False friends (words that look alike but mean something else) were left out of the total. They get their own article.

The 79 that are identical

These are the easiest: you read them and you know them. Some that sit among the 2,000 most common:

• idea, plan, real, final, normal, total
• hospital, hotel, animal, radio, video, taxi
• chocolate, pizza, piano, metal, color, honor
• doctor, actor, director, inspector, chef, club

The spelling is the same, but the sound changes. In Spanish every vowel is pronounced clearly and the h is silent, so hotel sounds like "o-TEL" and idea like "ee-DEH-ah".

The rules that unlock words

This is the most useful part. Some English endings have a fixed partner in Spanish. Once you know the rule, you can understand, and often build, Spanish words you have never seen. The numbers show how many of the 2,000 English words follow each rule.

-tion and -sion = -ción and -sión (21 words)

The best-known rule. Station is estación, information is información, situation is situación, attention is atención, decision is decisión, conversation is conversación, operation is operación.

-ly = -mente (26 words)

The English adverb ends in -ly, the Spanish one in -mente. Really is realmente, probably is probablemente, exactly is exactamente, finally is finalmente, obviously is obviamente, immediately is inmediatamente.

-al = -al (26 words)

Special is especial, national is nacional, natural is natural, local is local. Note the extra e in especial: native Spanish words don't start with s plus a consonant.

-ent and -ant = -ente and -ante (16 words)

Different is diferente, important is importante, president is presidente, patient is paciente, client is cliente, excellent is excelente, restaurant is restaurante.

-y and -ry = -ía, -ia and -rio (14 words)

Family is familia, story and history are both historia, memory is memoria, energy is energía, theory is teoría, mystery is misterio, necessary is necesario.

-or = -or or -dor (10 words)

Doctor, actor, color and favor don't change at all. Governor becomes gobernador.

-ty = -dad (9 words)

Security is seguridad, opportunity is oportunidad, society is sociedad, community is comunidad, reality is realidad, university is universidad.

-ct = -cto (9 words)

Perfect is perfecto, contact is contacto, project is proyecto, correct is correcto, effect is efecto, direct is directo. Two drop the c: respect is respeto and contract is contrato.

-ic and -ical = -ico and -ica (8 words)

Music is música, public is público, medical is médico, fantastic is fantástico, political is político, traffic is tráfico.

-ence, -ance and -ency = -encia and -ancia (8 words)

Experience is experiencia, evidence is evidencia, difference is diferencia, emergency is emergencia, science is ciencia, distance is distancia.

-able and -ible = -able and -ible (7 words)

Almost nothing changes. Possible is posible, terrible is terrible, incredible is increíble, responsible is responsable.

The smaller rules

• -ment = -mento or -miento (6): apartamento, departamento, documento, movimiento (movement), tratamiento (treatment).
• -ous = -oso (4): nervioso, famoso, delicioso, curioso.
• -ure = -ura (4): figura, criatura, cultura, tortura.
• -ate in verbs = -ar (4): create is crear, celebrate is celebrar, separate is separar, investigate is investigar.
• -ive = -ivo (1 among the 2,000): positivo.
• -ist = -ista (1): artista.

Why the rules matter more than they seem

The counts above only cover the first 2,000 English words. In the next 10,000 word forms from the same source, our estimate is about 196 words ending in -tion or -sion, 92 in -al, 89 in -ic, 69 in -y and 60 in -ly. It's an order-of-magnitude estimate (it counts forms, not unique words), but the point holds: the more advanced the vocabulary, the closer English and Spanish get. Long, formal words like responsabilidad and comunicación look scary, and they are some of the easiest for an English speaker.

The 422 that are similar

Many words follow no rule and still give themselves away:

• persona (person), nombre (name), minuto (minute), hora (hour)
• problema (problem), momento (moment), número (number), razón (reason)
• policía (police), carro (car), bebé (baby), escuela (school)
• punto (point), orden (order), parte (part), promesa (promise)

Reading them is easy. Hearing them is another story, because Spanish pronunciation and rhythm are different. That's where conversation helps: meeting the word inside a sentence trains your ear.

Where to see these words in use

In Pollyfriends, conversations lean on the words you already know first, and every new word shows a translation and an example with one tap. The Spanish-speaking friends are AI characters who live in Mexico. Hugo, a former history teacher who now drives for a ride app in Mexico City, tells you the story of every street, and Renata, a private Spanish tutor, explains whatever gets confusing.

If you like, meet the Spanish-speaking friends and count how many of these words turn up in the very first message.