What Does -ísimo Mean in Spanish? Muchísimo and Buenísimo Explained

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Spanish speakers often add -ísimo or -ísima to the end of an adjective:

These forms are commonly translated with English words such as:

However, -ísimo is not simply a longer version of muy.

The ending changes according to gender and number, some words undergo spelling changes, and forms such as muchísimo can behave differently from ordinary adjectives.

There is also an important difference between:

In this article, we will learn how -ísimo/-ísima works and examine two especially common words: muchísimo and buenísimo.

What Does -ísimo Mean in Spanish?

-Ísimo is a Spanish suffix used primarily to express an extreme degree of an adjective or adverb.

In traditional grammar, forms such as buenísimo are often called absolute superlatives.

The core image is:

The suffix often adds an expressive or emotional tone. A speaker who says buenísimo normally sounds more enthusiastic than a speaker who simply says bueno.

How to Pronounce -ísimo

The suffix contains a written accent:

The forms are:

The written accent is not optional. The correct forms are:

People frequently omit accents when typing informal search queries or messages, but articles and normal Spanish writing should include them.

Does -ísimo Mean “The Most” or “The Best”?

Not usually.

This is one of the most important distinctions for beginners.

-Ísimo expresses an extreme degree without necessarily comparing one person or thing with a group.

The first sentence describes the restaurant as extremely good.

The second compares it with the other restaurants in the city and places it at the top.

-ísimo Is Traditionally Called an Absolute Superlative

Spanish grammar traditionally distinguishes between two ideas:

Modern grammatical descriptions often treat the second type as an extreme-degree or elative form because it does not behave exactly like a comparative superlative.

For a beginner, the practical distinction is simple:

The Four Forms: -ísimo, -ísima, -ísimos and -ísimas

Adjectives ending in -ísimo normally agree with the gender and number of the noun they describe.

El libro es larguísimo.
The book is extremely long.

La reunión fue larguísima.
The meeting was extremely long.

Los libros son larguísimos.
The books are extremely long.

Las reuniones fueron larguísimas.
The meetings were extremely long.

How to Form Words with -ísimo

With many adjectives ending in -o or -a, remove the final vowel and add the appropriate form of -ísimo.

Adjectives ending in other letters can also take the suffix:

However, formation is not entirely mechanical. Some words require spelling changes or have traditional alternative forms.

Common Spelling Changes Before -ísimo

Words Ending in -co: c Becomes qu

The spelling changes to preserve the hard k sound before i.

La comida está riquísima.
The food is incredibly delicious.

Words Ending in -go: g Becomes gu

The spelling gu preserves the hard g sound before i.

El viaje fue larguísimo.
The trip was extremely long.

Words Ending in -z: z Becomes c

Estamos felicísimos con el resultado.
We are extremely happy with the result.

Some Words Add -císimo

Some adjectives ending in -n form an ending such as -císimo.

Can Every Adjective Take -ísimo?

No.

The suffix works most naturally with gradable adjectives: qualities that can logically exist in different degrees.

Other adjectives describe categories or relationships rather than a scalable quality.

For example, a word meaning “medical,” “wooden,” or “weekly” may not naturally accept -ísimo in its ordinary relational meaning.

Some relational adjectives can take the suffix when speakers reinterpret them expressively:

Es una costumbre mexicanísima.
It is an extremely Mexican / unmistakably Mexican custom.

Here, mexicanísima does not mean that the custom is mathematically more Mexican. It means that the custom strongly displays qualities associated with Mexico.

-ísimo vs. Muy: What Is the Difference?

Spanish has two common ways to express a high degree:

They can often describe similar situations, but the tone may differ.

Compare:

The second sentence often conveys more enthusiasm.

Can You Say Muy Buenísimo?

In standard usage, speakers normally choose one of the two methods:

Using both muy and -ísimo repeats the same basic degree-marking function.

You may occasionally hear combinations such as muy buenísimo for humor, exaggeration, childlike speech, advertising, or deliberate emotional emphasis.

However, beginners should not use it as the normal pattern.

Muchísimo Meaning in Spanish

Muchísimo is the extreme-degree form related to mucho.

Depending on its grammatical function, it can mean:

Its four forms are:

However, muchísimo does not always change form. It depends on how the word functions in the sentence.

Muchísimo Before a Noun

When muchísimo modifies a noun, it agrees with the noun’s gender and number.

Necesitamos muchísimo tiempo.
We need a great deal of time.

Ella tiene muchísima energía.
She has an enormous amount of energy.

Compraron muchísimos regalos.
They bought a huge number of gifts.

Había muchísimas personas en la plaza.
There were a great many people in the square.

Muchísima Agua: Agreement with Feminine Agua

The noun agua is grammatically feminine.

Spanish normally says el agua in the singular because the noun begins with a stressed a sound. However, adjectives and quantifiers still reveal its feminine gender.

Therefore:

Muchísimo After a Verb

When muchísimo modifies a verb, it functions as an adverb and remains in the masculine singular form.

The ending does not change according to the subject:

The subject changes, but the adverb muchísimo remains unchanged.

Muchísimo as a Pronoun

Muchísimo can also stand in place of a previously understood noun.

¿Cuántos libros compraste?
How many books did you buy?

Muchísimos.
A great many.

¿Había personas en el evento?
Were there people at the event?

Sí, muchísimas.
Yes, a huge number.

In this use, the form agrees with the omitted but understood noun:

Mucho vs. Muy vs. Muchísimo

These three forms are related, but they do not appear in the same positions.

Compare:

Muchísimas Gracias Meaning

Muchísimas gracias is a very common and emphatic way to say:

The form is muchísimas because gracias is a feminine plural noun.

Therefore:

Muchísimas gracias por tu ayuda.
Thank you so much for your help.

Muchísimas gracias a todos.
Thank you all very much.

Another emphatic expression is mil gracias, literally “a thousand thanks.” It is not necessarily stronger or weaker in a measurable way; both expressions communicate warm gratitude. See What Does Mil Gracias Mean in Spanish? for a detailed comparison of its meaning and tone.

Buenísimo Meaning in Spanish

Bუნísimo is the extreme-degree form of bueno.

Bுனísimo should be written buenísimo.

Depending on context, natural English translations include:

El libro es buenísimo.
The book is excellent.

La película estuvo buenísima.
The movie was amazing.

La comida está buenísima.
The food is delicious.

Fue una idea buenísima.
It was an excellent idea.

Why Is It Buenísimo and Not Buenoísimo?

The final -o of bueno is removed before the suffix is added:

The common modern form preserves the ue sound of bueno.

A learned form bonísimo also exists, but it is much less common and can sound highly formal, literary, or unusual in ordinary conversation.

For a beginner, buenísimo is the form to learn and use.

Buenísimo with Masculine, Feminine and Plural Nouns

Like other adjectives, buenísimo agrees with the noun it describes.

Buenísimo for Food

When speakers use buenísimo to describe food or drink, a natural English translation is often “delicious.”

Este pastel está buenísimo.
This cake is delicious.

La sopa está buenísima.
The soup is delicious.

Estos tacos están buenísimos.
These tacos are incredibly good.

The expression describes the speaker’s enthusiastic evaluation of the food.

Riquísimo is another extremely common word for delicious food:

The two overlap strongly when talking about taste. Riquísimo focuses more directly on delicious flavor, while buenísimo is a broader positive evaluation.

Buenísimo with Ser and Estar

Both ser and estar can appear with buenísimo, but the context changes.

Ser buenísimo

Ser often presents the quality as a characteristic, general evaluation, or identifying description.

El libro es buenísimo.
The book is excellent.

Ella es buenísima profesora.
She is an excellent teacher.

In the second sentence, buenísima evaluates her ability or quality as a teacher.

Estar buenísimo

Estar commonly evaluates a particular condition, experience, result, taste, or appearance.

El pastel está buenísimo.
The cake is delicious.

La fiesta estuvo buenísima.
The party was amazing.

In some contexts, saying that a person está buenísimo or está buenísima can mean that the person is extremely physically attractive.

This use is informal and can sound objectifying, flirtatious, or inappropriate depending on the relationship and situation.

Buenísimo as a Stand-Alone Reaction

Speakers can use ¡Buenísimo! by itself as an enthusiastic reaction.

Possible English translations include:

In this stand-alone use, buenísimo often reacts to an idea, plan, result, or piece of news.

Buenísimo vs. Muy Bueno vs. Excelente

Compare:

Bუნísimo is especially common when a speaker expresses personal enthusiasm. In more formal evaluation, excelente may fit better.

-ísimo vs. -ito: Opposite Meanings?

Both -ísimo and -ito are suffixes that can add the speaker’s attitude to a word, but their primary functions are different.

For example:

The meanings can overlap emotionally, but the grammatical focus differs.

For a detailed explanation of the diminutive suffix, see What Does -ito/-ita Mean in Spanish?

Can -ísimo Be Added to Adverbs?

Yes. Several common adverbs accept -ísimo.

La estación está cerquísima.
The station is extremely close.

Viven lejísimos de aquí.
They live extremely far from here.

Llegamos tardísimo.
We arrived extremely late.

Notice that lejísimos commonly ends in -os even though it functions adverbially. It should be learned as a conventional form rather than analyzed as agreement with a plural noun.

Common Spanish Words Ending in -ísimo

Natural Conversation Examples

Conversation 1: An Excellent Restaurant

Bுனísimo evaluates the restaurant as a whole, while riquísima focuses on the taste of the food.

Conversation 2: A Very Difficult Exam

The speaker uses dificilísimo by itself because the omitted subject, el examen, is understood.

Conversation 3: Expressing Gratitude

Muchísimas agrees with the feminine plural noun gracias.

Conversation 4: A Huge Amount of Work

Here, muchísimo agrees with the masculine singular noun trabajo.

Conversation 5: An Extremely Long Journey

Conversation 6: Responding to a Plan

A Beginner’s Method for Understanding -ísimo

Common Mistakes with -ísimo, Muchísimo and Buenísimo

Mistake 1: Omitting the Accent Mark

Mistake 2: Translating -ísimo as “The Most” Every Time

Bুনísimo usually means “extremely good,” not “the best.”

Mistake 3: Forgetting Gender and Number Agreement

Mistake 4: Changing Adverbial Muchísimo

When it modifies a verb, muchísimo is invariable.

Mistake 5: Saying Muchísimo Bueno

Use:

Mistake 6: Saying Muy Buenísimo as the Normal Pattern

Standard usage normally avoids combining both degree markers.

Mistake 7: Ignoring Spelling Changes

Mistake 8: Assuming Every Adjective Accepts the Suffix Naturally

The suffix works best with qualities that can logically exist in degrees. Do not automatically add it to every adjective.

Mistake 9: Overusing -ísimo

The suffix is expressive. Using it in every sentence can make your Spanish sound exaggerated.

Native speakers naturally alternate among:

Mistake 10: Translating Every Form Literally

Natural translation depends on context:

Frequently Asked Questions About -ísimo

What does -ísimo mean in Spanish?

-Ísimo/-ísima is a suffix that expresses an extreme degree of a quality. It often corresponds to “very,” “extremely,” “incredibly,” or “exceptionally” in English.

What does muchísimo mean?

Muchísimo can mean “very much,” “so much,” “a great deal,” or “an enormous amount.” Before a noun, its ending agrees with the noun. When it modifies a verb, it normally remains muchísimo.

What does buenísimo mean?

Bունísimo means “extremely good,” “excellent,” “amazing,” or, when referring to food, “delicious.” It can also stand alone as a reaction meaning “Great!” or “Excellent!”

Is buenísimo the same as the best?

No. Bունísimo normally means “extremely good.” “The best” is expressed with el mejor, la mejor, los mejores, or las mejores.

What is the difference between muy bueno and buenísimo?

Both express a high degree of goodness. Muy bueno is neutral and broadly usable, while buenísimo is often stronger, more expressive, and more enthusiastic.

Can you say muy buenísimo?

Standard usage normally avoids combining muy with an adjective already ending in -ísimo. Use either muy bueno or buenísimo. The doubled form may occur for deliberate humor or exaggeration.

Why is it muchísimas gracias?

Gracias is feminine plural, so the agreeing form is muchísimas: muchísimas gracias.

Why does muchísimo have an accent?

The written accent marks the stressed syllable: mu-CHÍ-si-mo. All forms of the suffix retain this accent: -ísimo, -ísima, -ísimos, and -ísimas.

Can -ísimo be used with adverbs?

Yes. Common forms include cerquísima, lejísimos, prontísimo, tardísimo, and tempranísimo.

Can every Spanish adjective use -ísimo?

No. It is most natural with gradable adjectives describing qualities that can increase or decrease. Some adjectives require spelling changes, have irregular forms, or do not naturally accept the suffix.

-ísimo, Muchísimo and Buenísimo: Summary

Related Guide

Want the full picture of how Spanish suffixes change meaning? Read our complete hub guide: Spanish Diminutives and Suffixes Explained.