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A2 adjective #3,500 most common 9 min read

ácido

Top 3,500

Practice it Examples Notes & Tips ácido in 30 Seconds

Explanation ácido in your Level:

At the A1 level, you only need to know 'ácido' in its most basic form. It is an adjective used to describe the taste of certain fruits, specifically lemons (limões) and oranges (laranjas). You should learn it alongside other basic taste words like 'doce' (sweet) and 'salgado' (salty). At this stage, don't worry about the chemical or metaphorical meanings. Focus on simple sentences like 'O limão é ácido.' Remember that the word changes to 'ácida' if the thing you are describing is feminine, like 'esta fruta'. You will mostly hear this in the context of food and drinks. It is a helpful word to have when you are at a market or a restaurant and want to describe what you are eating. Try to associate the word with the physical sensation of a sour lemon. This will help you remember it easily. In A1, we keep things simple and literal. You might also see it on signs for 'suco de limão' (lemon juice), which is naturally acidic. Just remember: if it makes your mouth pucker, it is 'ácido'.

At the A2 level, you begin to use 'ácido' in slightly more complex sentences and common phrases. You might describe a juice as being 'muito ácido' (very acidic) or 'pouco ácido' (not very acidic). You will also learn the feminine plural form 'ácidas' and the masculine plural 'ácidos'. For example, 'estas laranjas são ácidas'. You might also encounter the word in basic health contexts, such as 'estômago ácido' (acid stomach) if you are feeling unwell. At this level, you are starting to see the word in more daily life situations beyond just fruit. You should also be aware of the noun form 'o ácido', although you won't use it much yet. A common mistake at this level is using 'ácido' when you mean 'azedo' (spoiled). Remember, 'ácido' is for the natural taste of a lemon, while 'azedo' is often for milk that has gone bad. You will also start to see the word in simple science contexts if you read basic news or educational materials in Portuguese. It's a versatile word that helps you be more specific about your preferences and physical sensations.

By B1, you should be comfortable using 'ácido' metaphorically. This is when you start to describe a person's sense of humor as 'humor ácido' or a remark as 'comentário ácido'. You understand that this doesn't mean the person tastes like a lemon, but that their words are sharp and perhaps a bit sarcastic. You will also encounter the word in environmental and news contexts, such as 'chuva ácida' (acid rain). Your vocabulary is expanding to include related words like 'acidez' (acidity). You can now talk about the 'acidez do vinho' (the acidity of the wine) or the 'acidez do solo' (the acidity of the soil). You are beginning to notice how the word is used in magazines and newspapers to describe social and political critiques. In B1, you are expected to handle the gender and number agreement perfectly. You also start to distinguish between 'ser ácido' (to be inherently acidic) and 'estar ácido' (to be acidic in a specific moment or state). This level is about moving from literal descriptions to more abstract and nuanced communication.

At the B2 level, you use 'ácido' with precision in professional and academic contexts. You might discuss the 'ácido hialurônico' in a conversation about skincare or 'ácido acetilsalicílico' (aspirin) in a medical context. You are familiar with the word's role in chemistry and biology. Metaphorically, you can use 'ácido' to describe complex social dynamics, such as a 'crítica ácida' in a literary review. You understand the nuance between 'ácido', 'mordaz', and 'sarcástico'. You can participate in discussions about the environment, explaining the causes and effects of 'chuva ácida' on ecosystems. Your ability to use the word in different registers—from informal kitchen talk to formal scientific reports—is well-developed. You also recognize common idioms and collocations, such as 'equilíbrio ácido-base'. At this stage, you are not just using the word; you are choosing it over other synonyms because it carries the exact nuance you want to convey. You are also more aware of the historical and cultural references that might involve the word, such as famous 'ácido' wits in Portuguese literature.

At the C1 level, your use of 'ácido' is sophisticated and natural. You can use it to describe subtle nuances in art, literature, and social behavior. You might analyze a filmmaker's 'olhar ácido' (acidic gaze) on society, implying a sharp, uncompromising, and perhaps cynical perspective. You are comfortable with technical terms in various fields, from 'ácidos graxos' (fatty acids) in nutrition to 'decapagem ácida' in engineering. You can use the word in high-level debates about public policy or scientific research. Your understanding of the word includes its etymological roots and how they influence its meaning in modern Portuguese. You can play with the word's double meanings in creative writing or complex arguments. At this level, you also understand the subtle cultural differences in how 'ácido' humor is perceived in different Portuguese-speaking countries. You use the word with a high degree of idiomatic accuracy, and you can explain its nuances to others. Your command of 'ácido' reflects a deep immersion in the language and its various professional and intellectual domains.

At the C2 level, you have a masterly command of 'ácido' and all its derivatives. You can use it with the same ease and nuance as a highly educated native speaker. You might use it in a philosophical treatise to describe a 'razão ácida' that dissolves traditional beliefs, or in a high-level political analysis of 'discurso ácido'. You are fully aware of the word's evocative power and use it to create specific rhetorical effects. You can navigate the most technical scientific literature where 'ácido' is a fundamental concept, as well as the most avant-garde literature where it might be used in highly metaphorical ways. Your understanding of the word is holistic, connecting its physical, chemical, emotional, and social dimensions. You can effortlessly switch between these meanings, often using the word to bridge different fields of thought. At this level, 'ácido' is just one of many tools in your extensive linguistic repertoire, used with perfect timing and precision to convey complex, multi-layered ideas. You are also sensitive to the most subtle connotations and historical echoes the word might carry in various Lusophone cultures.

Practice it Examples Notes & Tips

ácido in 30 Seconds

Ácido primarily means sour or acidic in taste, like a lemon or vinegar.
It is also a chemical term for substances with a pH lower than 7.
Metaphorically, it describes sharp, biting, or sarcastic humor and criticism.
As an adjective, it must agree in gender and number with the noun it modifies.

The Portuguese word ácido is a versatile adjective that primarily describes a sharp, sour, or biting quality. At its most literal level, it refers to the gustatory sensation one experiences when consuming substances like lemons, limes, or vinegar. In the realm of chemistry, it describes substances with a pH lower than seven. However, its utility extends far beyond the kitchen or the laboratory. In social and literary contexts, ácido is frequently employed to describe a person's temperament, a specific type of humor, or a critical remark that is particularly sharp, biting, or sarcastic.

Literal Taste: When you bite into a green apple or sip unsweetened lemonade, the immediate sensation on the sides of your tongue is described as ácido. It is the opposite of doce (sweet) or amargo (bitter).

Este suco de laranja está muito ácido, preciso colocar mais açúcar.

Translation: This orange juice is very acidic; I need to add more sugar.

In a metaphorical sense, calling someone's humor ácido implies that their jokes are not just funny, but carry a certain edge or sting. This is often associated with irony or satire. If a critic writes an crítica ácida, they aren't just giving a negative review; they are being pointedly harsh and perhaps even a bit cruel in their observations. This dual nature of the word—moving from a physical sensation to a personality trait—is a common feature in many Romance languages, but in Portuguese, the nuance often leans toward intellectual sharpness.

Chemical Property: In technical settings, ácido functions as both an adjective and a noun. As an adjective, it describes the nature of a solution (e.g., solo ácido - acidic soil). As a noun, it refers to the substance itself (e.g., ácido sulfúrico).

O humor dele é tão ácido que às vezes as pessoas se sentem ofendidas.

Translation: His humor is so biting that sometimes people feel offended.

Furthermore, the word appears in environmental discussions, such as chuva ácida (acid rain), which is a significant topic in contemporary Portuguese-speaking news outlets. Understanding the breadth of ácido allows a learner to navigate conversations ranging from gastronomy and agriculture to social commentary and environmental science. It is a high-frequency word that bridges the gap between basic sensory descriptions and complex abstract concepts.

Environmental Context: The term chuva ácida is used globally to describe precipitation that has become acidic due to atmospheric pollution, a common topic in Portuguese educational materials.

A chuva ácida pode danificar monumentos históricos feitos de mármore.

Using ácido correctly in Portuguese requires attention to gender and number agreement, as it is an adjective. Like most Portuguese adjectives, it must match the noun it modifies. The masculine singular is ácido, the feminine singular is ácida, the masculine plural is ácidos, and the feminine plural is ácidas. Placement is also key: it typically follows the noun it describes, which is the standard position for descriptive adjectives in Portuguese.

Agreement Rules: If you are talking about 'o vinho' (masculine), you say 'vinho ácido'. If you are talking about 'a fruta' (feminine), you say 'fruta ácida'.

Estas maçãs são muito ácidas para o meu gosto.

Translation: These apples are too acidic for my taste.

In more advanced usage, ácido can be used to intensify a description. For example, when discussing a person's reaction, you might say they gave an resposta ácida (a biting response). Here, the word moves from the physical domain to the emotional/intellectual domain. It is important to note that while 'sour' in English can sometimes mean 'grumpy', ácido in Portuguese specifically denotes a sharp, intellectual sting rather than just a bad mood.

O cientista mediu o nível ácido da solução no laboratório.

When constructing sentences about food, you will often find ácido paired with verbs like ser (to be - permanent quality) or estar (to be - temporary state). For instance, 'O limão é ácido' (The lemon is inherently acidic), versus 'Este molho está muito ácido' (This sauce is currently too acidic, perhaps because of how it was prepared). Understanding this distinction helps in sounding more like a native speaker.

Common Verb Pairings: Ser + Ácido: Inherent traits (lemons, chemicals). Estar + Ácido: Current states or results (cooking, wine aging).

Aquele comediante é conhecido por seu comentário ácido sobre a política atual.

You will encounter the word ácido in a variety of daily and specialized settings across the Lusophone world. In a typical Brazilian or Portuguese household, the word is a staple of the kitchen. If a fruit isn't ripe yet, it might be described as ácida. If a salad dressing has too much vinegar, someone might complain that it is ácido demais. It's a fundamental part of the vocabulary for anyone discussing food, health, and digestion.

In the Kitchen: Chefs often talk about 'equilíbrio ácido' (acid balance) in dishes, referring to the use of lime, lemon, or vinegar to brighten flavors.

Cuidado com o abacaxi, ele parece estar muito ácido hoje.

Translation: Careful with the pineapple; it seems to be very acidic today.

Beyond the domestic sphere, ácido is a mainstay in media and journalism. Political commentators are frequently described as having an estilo ácido. When a politician gives a speech that is particularly critical of an opponent, the news might headline it as an ataque ácido. This usage is very common in newspapers like 'Folha de S.Paulo' or 'Público', where intellectual rigor and sharp wit are valued in opinion pieces.

A revista publicou uma crítica ácida sobre o novo filme do diretor.

In the scientific and industrial world, the word is unavoidable. From skincare products containing ácido hialurônico (hyaluronic acid) to agricultural reports on the acidez of the soil in the Cerrado region of Brazil, the term is used with precision. Students in secondary school learn about ácidos e bases in chemistry class, ensuring that every native speaker has a baseline understanding of the word's technical meaning.

Beauty and Health: You will see 'ácido' on almost every skincare bottle in Portuguese pharmacies, such as 'ácido glicólico' or 'ácido salicílico'.

O dermatologista recomendou um creme com ácido hialurônico para a pele.

One of the most frequent mistakes English speakers make when learning Portuguese is confusing ácido with azedo. While both can be translated as 'sour' in English, they are not always interchangeable. Ácido is a more formal, scientific, or inherent description. Azedo, on the other hand, often carries a negative connotation of something being fermented or spoiled. For example, you would say 'limão ácido' but 'leite azedo' (spoiled milk). Using 'leite ácido' would sound like a chemical experiment rather than a kitchen mishap.

Ácido vs. Azedo: Use ácido for lemons, chemistry, and sharp wit. Use azedo for spoiled food or a person who is simply in a bad mood (a 'sour' person).

Não beba esse leite, ele está azedo (NOT ácido).

Another common pitfall is gender agreement. Because ácido ends in '-o', learners often forget to change it to ácida when modifying feminine nouns like chuva (rain) or crítica (criticism). 'Chuva ácido' is a common error; it must be 'chuva ácida'. Similarly, when used as a noun, the word is always masculine: 'O ácido' (The acid), even if the context seems feminine.

Finally, learners sometimes struggle with the placement of the adjective. While you can occasionally place adjectives before the noun in Portuguese for poetic effect, placing ácido before the noun (e.g., 'o ácido limão') sounds very dramatic and archaic. In 99% of daily conversations, keep it after the noun: 'o limão ácido'. This ensures your Portuguese sounds natural and contemporary.

Placement Error: Incorrect: 'Ele tem um ácido humor.' Correct: 'Ele tem um humor ácido.'

A crítica ácida do jornalista causou polêmica.

To expand your vocabulary beyond ácido, it's helpful to understand its synonyms and related terms, each with its own specific flavor. Depending on whether you're talking about food, chemistry, or personality, there are several alternatives that might be more precise. For example, azedo is the closest synonym for taste, but as discussed, it often implies spoilage or a simpler, less 'chemical' sourness.

Azedo vs. Ácido: Azedo: More common for food that is naturally sour or has gone bad. Ácido: More formal, used for chemicals or sharp wit.

Este iogurte está azedo, acho que passou da validade.

When describing a person's sharp tongue, you might use mordaz (mordant/biting) or sarcástico (sarcastic). Mordaz is a high-level vocabulary word that specifically refers to a critical style that 'bites'. It's a great alternative to ácido in a literary or academic context. Another related term is adstringente (astringent), which describes that 'puckering' sensation you get from unripe bananas or certain wines, often confused with acidity but physically different.

Mordaz vs. Ácido: Mordaz: Implies a deeper, more intentional desire to criticize or wound. Ácido: Can simply describe a sharp style of humor without necessarily being malicious.

O autor tem um estilo mordaz que cativa os leitores.

Lastly, in technical contexts, you might hear corrosivo (corrosive). While an acid can be corrosive, corrosivo is also used metaphorically to describe something that slowly destroys or eats away at something else, like crítica corrosiva. Understanding these nuances will help you choose the right word for the right situation, making your Portuguese more expressive and accurate.

Corrosivo vs. Ácido: Corrosivo: Focuses on the destructive power. Ácido: Focuses on the chemical nature or the sharp sensation.

How Formal Is It?

Formal

Neutral

Informal

Child friendly

Slang

Fun Fact

The word 'ácido' is related to 'aço' (steel) in Portuguese, as both share a Latin root related to sharpness ('acies').

Pronunciation Guide

UK /ˈasidu/

US /ˈasidu/

The stress is on the first syllable: Á-ci-do.

Rhymes With

pálido válido rápido cálido lúcido úmido sólido líquido

Common Errors

Pronouncing the 'c' as a 'k' sound (it should be 's').
Putting the stress on the second syllable.
Not making the 'á' open enough.
Forgetting the 'i' sound in the middle.
Pronouncing the final 'o' too strongly like 'oh' instead of a soft 'u'.

Difficulty Rating

Reading 2/5

Easy to recognize as a cognate of 'acid'.

Writing 3/5

Requires attention to gender and number agreement.

Speaking 3/5

Pronunciation of the stressed 'á' and soft 'o' is key.

Listening 2/5

Distinctive sound makes it easy to catch in conversation.

What to Learn Next

Prerequisites

doce limão fruta gosto muito

Learn Next

azedo amargo salgado sarcástico mordaz

Advanced

acidez corrosivo adstringente alcalino neutralizar

Grammar to Know

Gender agreement of adjectives ending in -o.

O suco é ácido. A fruta é ácida.

Pluralization of adjectives ending in -o.

Os sucos são ácidos. As frutas são ácidas.

Position of descriptive adjectives after the noun.

Um comentário ácido (not 'um ácido comentário').

Use of 'ser' for inherent qualities.

O limão é ácido.

Use of 'estar' for temporary states.

O café está ácido hoje.

Examples by Level

O limão é muito ácido.

The lemon is very acidic.

Masculine singular agreement with 'limão'.

Eu não gosto de suco ácido.

I don't like acidic juice.

Adjective follows the noun 'suco'.

Esta laranja está ácida?

Is this orange acidic?

Feminine singular agreement with 'laranja'.

A maçã verde é ácida.

The green apple is acidic.

Feminine singular agreement with 'maçã'.

O café está um pouco ácido hoje.

The coffee is a bit acidic today.

Use of 'estar' for a temporary state.

Frutas ácidas são boas para a saúde.

Acidic fruits are good for health.

Feminine plural agreement with 'frutas'.

Você prefere doce ou ácido?

Do you prefer sweet or acidic?

Using adjectives as categories of taste.

Este molho de tomate é ácido.

This tomato sauce is acidic.

Masculine singular agreement with 'molho'.

O solo desta região é muito ácido para plantar flores.

The soil in this region is too acidic to plant flowers.

Masculine singular agreement with 'solo'.

Muitas pessoas sofrem de refluxo ácido.

Many people suffer from acid reflux.

Common medical collocation.

O vinho branco costuma ser mais ácido que o tinto.

White wine is usually more acidic than red wine.

Comparative structure with 'mais... que'.

Não use produtos muito ácidos na pele sensível.

Do not use very acidic products on sensitive skin.

Masculine plural agreement with 'produtos'.

A chuva ácida pode ser um problema nas cidades grandes.

Acid rain can be a problem in big cities.

Feminine singular agreement with 'chuva'.

Eu sinto um gosto ácido na boca.

I feel an acidic taste in my mouth.

Adjective modifying 'gosto'.

O iogurte natural é naturalmente um pouco ácido.

Natural yogurt is naturally a bit acidic.

Adverb 'naturalmente' modifying the adjective.

Estes produtos químicos são ácidos e perigosos.

These chemicals are acidic and dangerous.

Masculine plural agreement.

Ele fez um comentário ácido sobre o meu novo corte de cabelo.

He made a biting comment about my new haircut.

Metaphorical use for sharp/biting humor.

A crítica ácida do jornalista destruiu a reputação do restaurante.

The journalist's biting criticism destroyed the restaurant's reputation.

Feminine agreement with 'crítica'.

Ela tem um humor ácido que nem todos entendem.

She has a biting humor that not everyone understands.

Common collocation 'humor ácido'.

O nível ácido da piscina precisa ser controlado semanalmente.

The acid level of the pool needs to be checked weekly.

Technical use in maintenance.

Muitos refrigerantes contêm ácido fosfórico na sua composição.

Many soft drinks contain phosphoric acid in their composition.

Noun use: 'o ácido'.

O filme é uma sátira ácida à sociedade moderna.

The movie is a biting satire of modern society.

Feminine agreement with 'sátira'.

Senti uma resposta ácida vinda do meu chefe hoje de manhã.

I felt a biting response coming from my boss this morning.

Feminine agreement with 'resposta'.

A acidez do estômago pode causar azia.

Stomach acidity can cause heartburn.

Related noun 'acidez'.

O ácido hialurônico é amplamente utilizado na indústria de cosméticos.

Hyaluronic acid is widely used in the cosmetics industry.

Specific chemical noun.

A chuva ácida é causada pela emissão de gases poluentes na atmosfera.

Acid rain is caused by the emission of pollutant gases into the atmosphere.

Environmental science context.

O autor utiliza um tom ácido para descrever a hipocrisia da elite.

The author uses a biting tone to describe the hypocrisy of the elite.

Literary analysis context.

É necessário neutralizar o solo ácido antes de iniciar o plantio.

It is necessary to neutralize the acidic soil before starting to plant.

Agricultural context.

O ácido sulfúrico é uma substância altamente corrosiva.

Sulfuric acid is a highly corrosive substance.

Chemistry context.

O debate político foi marcado por trocas de insultos ácidos.

The political debate was marked by exchanges of biting insults.

Masculine plural agreement with 'insultos'.

A dieta ocidental costuma ser muito ácida para o organismo.

The Western diet is usually too acidic for the body.

Health and nutrition context.

O pH indica se uma solução é ácida, neutra ou básica.

The pH indicates if a solution is acidic, neutral, or basic.

Scientific definition context.

A obra é permeada por um olhar ácido sobre as instituições religiosas.

The work is permeated by a biting look at religious institutions.

High-level literary description.

A oxidação dos metais pode ser acelerada em ambientes ácidos.

The oxidation of metals can be accelerated in acidic environments.

Engineering and chemistry context.

Sua ironia ácida é sua marca registrada como colunista.

Her biting irony is her trademark as a columnist.

Feminine agreement with 'ironia'.

O metabolismo dos ácidos graxos é fundamental para a produção de energia.

The metabolism of fatty acids is fundamental for energy production.

Biology/Biochemistry context.

A crítica social ácida do filme incomodou os setores mais conservadores.

The film's biting social criticism bothered the more conservative sectors.

Complex noun phrase agreement.

O processo de decapagem ácida remove impurezas da superfície do aço.

The acid pickling process removes impurities from the steel surface.

Technical industrial terminology.

O texto apresenta uma análise ácida e desapaixonada da crise econômica.

The text presents a biting and dispassionate analysis of the economic crisis.

Academic/Journalistic register.

A deposição ácida afeta a biodiversidade dos lagos de alta montanha.

Acid deposition affects the biodiversity of high mountain lakes.

Environmental science terminology.

A prosa ácida de Thomas Bernhard é um desafio para qualquer tradutor.

Thomas Bernhard's biting prose is a challenge for any translator.

Literary criticism at a high level.

O ácido desoxirribonucleico carrega toda a informação genética dos seres vivos.

Deoxyribonucleic acid carries all the genetic information of living beings.

Scientific name for DNA.

A virulência ácida do seu discurso alienou até mesmo seus aliados mais próximos.

The biting virulence of his speech alienated even his closest allies.

Highly abstract and sophisticated use.

O equilíbrio ácido-base é vital para a homeostase do corpo humano.

Acid-base balance is vital for the homeostasis of the human body.

Advanced medical/biological terminology.

A sátira menipeia é conhecida por seu caráter ácido e transgressor.

Menippean satire is known for its biting and transgressive character.

Niche literary/historical context.

O pensamento ácido de Nietzsche questionou os fundamentos da moral cristã.

Nietzsche's biting thought questioned the foundations of Christian morality.

Philosophical context.

A lixiviação ácida é um processo comum na mineração de metais preciosos.

Acid leaching is a common process in the mining of precious metals.

Highly technical mining terminology.

Sua verve ácida esconde uma profunda melancolia e desilusão com o mundo.

His biting wit hides a deep melancholy and disillusionment with the world.

Sophisticated psychological description.

Common Collocations

chuva ácida

humor ácido

crítica ácida

ácido hialurônico

refluxo ácido

solo ácido

gosto ácido

ácido cítrico

ácido úrico

comentário ácido

Common Phrases

estar com o estômago ácido

— To have an acidic stomach or indigestion.

Estou com o estômago ácido hoje.

um tom ácido

— A sharp or biting tone of voice/writing.

Ele falou num tom ácido.

equilíbrio ácido

— Acid balance, often in cooking or chemistry.

O prato precisa de mais equilíbrio ácido.

reação ácida

— A sharp or negative reaction to something.

A proposta teve uma reação ácida.

olhar ácido

— A critical or biting way of looking at something.

Ele tem um olhar ácido sobre a vida.

palavras ácidas

— Harsh or biting words.

Suas palavras ácidas me magoaram.

estilo ácido

— A biting or sharp style, usually in writing.

O escritor é famoso pelo seu estilo ácido.

limpeza ácida

— Cleaning using acidic products.

Fizemos uma limpeza ácida no piso.

frutas ácidas

— Citrus fruits or other sour fruits.

Evite frutas ácidas se tiver gastrite.

ácido graxo

— Fatty acid, a term used in nutrition.

O ômega-3 é um ácido graxo essencial.

Often Confused With

ácido vs azedo

Often implies something is spoiled or fermented, while ácido is a natural property.

ácido vs amargo

Amargo is bitter (like unsweetened cocoa), while ácido is sour/acidic (like lemon).

ácido vs picante

Picante is spicy/hot, which is a different sensory experience entirely.

Idioms & Expressions

"língua ácida"

— To have a sharp tongue; to be prone to making biting or sarcastic remarks.

Cuidado com ela, tem uma língua ácida.

informal

"humor de ácido"

— A very dark, sharp, and biting sense of humor.

O show dele é puro humor de ácido.

informal

"cuspir ácido"

— To speak very harshly or angrily to someone.

Ele estava tão bravo que parecia cuspir ácido.

informal

"ácido como limão"

— Extremely sour or extremely biting in personality.

Aquele crítico é ácido como limão.

neutral

"banho de ácido"

— A very harsh or destructive experience or critique.

A reunião foi um verdadeiro banho de ácido.

informal

"mente ácida"

— A very sharp, critical, and analytical mind.

Ele tem uma mente ácida para a política.

neutral

"sorriso ácido"

— A sarcastic or knowing smile that carries a sting.

Ela me deu um sorriso ácido e saiu.

neutral

"ácido na ferida"

— To say something that makes a painful situation worse (similar to salt in a wound).

O comentário dele foi como ácido na ferida.

informal

"sangue ácido"

— To be a cold, sharp, or very critical person.

Ele tem sangue ácido, nunca elogia ninguém.

informal

"ácido puro"

— Something that is intensely biting or sarcastic.

O novo livro dele é ácido puro.

informal

Easily Confused

ácido vs azedo

Both translate to 'sour' in English.

Ácido is more clinical or inherent; azedo is more common for spoiled food or simple sourness.

Limão ácido vs. Leite azedo.

ácido vs amargo

Learners often mix up basic taste adjectives.

Amargo is bitter (coffee, dark chocolate); ácido is sour (lemon, vinegar).

Café amargo vs. Suco ácido.

ácido vs ácida

Gender agreement mistake.

Ácida is for feminine nouns; ácido is for masculine nouns.

Chuva ácida vs. Solo ácido.

ácido vs acidez

Confusing the noun with the adjective.

Acidez is the noun (acidity); ácido is the adjective (acidic).

A acidez do limão vs. O limão ácido.

ácido vs acidulado

Technical similarity.

Acidulado means slightly acidified or tangy; ácido is fully acidic.

Bala acidulada vs. Ácido puro.

Sentence Patterns

O/A [Substantivo] é ácido/a.

O limão é ácido.

Eu [verbo] [substantivo] ácido/a.

Eu bebo suco ácido.

Ele/Ela tem um [substantivo] ácido.

Ele tem um humor ácido.

A [substantivo] foi ácida.

A crítica foi ácida.

O nível de [substantivo] é ácido.

O nível de pH é ácido.

Um olhar ácido sobre [assunto].

Um olhar ácido sobre a política.

A [substantivo] ácida de [autor].

A prosa ácida de Machado de Assis.

Permeado por um caráter ácido.

O texto é permeado por um caráter ácido.

Word Family

Nouns

Verbs

Adjectives

How to Use It

frequency

High frequency in both daily speech and technical writing.

Common Mistakes

O leite está ácido. → O leite está azedo.
Use 'azedo' for spoiled food like milk.
Chuva ácido. → Chuva ácida.
'Chuva' is feminine, so the adjective must be 'ácida'.
Ele tem um ácido humor. → Ele tem um humor ácido.
Adjectives usually come after the noun in Portuguese.
O gosto é amargo (when meaning lemon). → O gosto é ácido.
Don't confuse bitter (amargo) with sour/acidic (ácido).
Eu sinto acidez (adjective). → Eu sinto um gosto ácido.
Use the adjective 'ácido' to describe the taste, not the noun 'acidez' in this context.

Tips

Gender Check

Always look at the noun. If it ends in 'a', use 'ácida'. If it ends in 'o', use 'ácido'.

Taste Buds

Associate 'ácido' with lemons and 'azedo' with spoiled milk to never mix them up again.

Humor Style

Use 'humor ácido' to describe someone who is funny in a sharp, slightly mean, or sarcastic way.

pH Scale

In a lab, remember that 'ácido' is anything below pH 7. It's the same word in Portuguese!

Skincare

Look for 'ácido' on labels in Portuguese pharmacies to find your favorite skincare ingredients.

Formal Writing

In academic texts, use 'ácido' to describe critical perspectives for a more sophisticated tone.

Brazilian Wit

Watch Brazilian talk shows to hear examples of 'humor ácido' in action.

Open 'A'

Don't swallow the first 'á'. It should be loud and clear: Á-ci-do.

Eco-Talk

Use 'chuva ácida' when discussing environmental issues to show off your B1+ vocabulary.

Stomach Issues

If you go to a doctor in a Portuguese-speaking country, 'estômago ácido' is a key phrase for indigestion.

Memorize It

Mnemonic

Think of an 'Acid' lemon that makes you 'A-ci-do' (A-see-do). Imagine the 'A' is as sharp as the taste.

Visual Association

Imagine a lemon with a sharp, spiky 'A' on top of it.

Word Web

limão vinagre química sarcasmo crítica azedo pH chuva

Challenge

Try to use 'ácido' in three different ways today: once for food, once for a chemical, and once for a movie review.

Word Origin

From the Latin 'acidus', meaning sour, sharp, or tart.

Original meaning: Originally used to describe the taste of vinegar or sour wine.

Romance (Latin root).

Cultural Context

Be careful when using 'ácido' to describe a person's personality; it can be a compliment for intelligence or an insult for being too harsh.

In English, 'acid' is often a noun first, whereas in Portuguese, 'ácido' is very commonly used as an adjective.

Millôr Fernandes (Brazilian writer known for acid wit) Eça de Queirós (Portuguese author with biting social critiques) Breaking Bad (popular show translated/dubbed in PT where 'ácido' is a frequent term)

Practice in Real Life

Real-World Contexts

In the Kitchen

Este molho está ácido.
Preciso de algo ácido.
O limão é ácido.
Acidez equilibrada.

In Science Class

O pH é ácido.
Ácido e base.
Reação ácida.
Ácido clorídrico.

Socializing

Humor ácido.
Comentário ácido.
Resposta ácida.
Língua ácida.

Skincare/Health

Ácido hialurônico.
Refluxo ácido.
Pele ácida.
Ácido úrico.

Environment

Chuva ácida.
Solo ácido.
Deposição ácida.
Nível ácido.

Conversation Starters

"Você gosta de frutas ácidas ou prefere as mais doces?"

"O que você acha do humor ácido de certos comediantes?"

"Você já teve problemas com refluxo ácido depois de comer?"

"Você usa algum creme com ácido hialurônico na sua rotina?"

"Você acha que a chuva ácida é um grande problema na sua cidade?"

Journal Prompts

Descreva uma vez que você comeu algo extremamente ácido e qual foi sua reação.

Escreva sobre um personagem de um livro ou filme que tem um humor ácido.

Como você equilibra a acidez na sua comida quando está cozinhando?

Pense em uma crítica ácida que você recebeu. Como você se sentiu?

Explique a importância de controlar o nível ácido em um laboratório ou piscina.

Frequently Asked Questions

10 questions

Ácido é um termo mais técnico e formal, usado para descrever a propriedade química ou o sabor natural de frutas cítricas. Azedo é usado para coisas que fermentaram ou estragaram, como o leite.

Sim, mas geralmente descreve o humor ou a forma de falar (humor ácido, resposta ácida), indicando sarcasmo ou ironia.

Diz-se 'chuva ácida'. Lembre-se de usar a forma feminina 'ácida' para concordar com 'chuva'.

Pode ser os dois. Como adjetivo: 'O suco é ácido'. Como substantivo: 'O ácido sulfúrico'.

O plural é 'ácidos' para o masculino e 'ácidas' para o feminino.

O 'á' é aberto, como em 'casa' ou 'pá'. A sílaba tônica é a primeira.

Sim, é um termo muito comum em farmácias e clínicas de estética no Brasil.

É um solo com pH baixo, comum em algumas regiões do Brasil, que precisa de tratamento para a agricultura.

Sim, pode se referir à droga LSD, mas é menos comum do que outras gírias hoje em dia.

O oposto mais comum é 'doce', mas em contextos químicos, o oposto é 'básico' ou 'alcalino'.