How to Use Mucho and Muy

Mucho and muy are two Spanish words with similar meanings which often get confused and switched by English speakers. But they are not interchangeable. Here are the rules for their usage.

Mucho as an Adjective

Mucho is an adjective. It translates to "a lot of," "many," or "much." Unlike most adjectives it is placed before nouns.

Ella tiene mucho dinero.
She has a lot of money.

Hay mucho trabajo.
There is much work.

No tenemos mucho tiempo.
We don't have much time.

Since it is an adjective, mucho also has other forms and needs to agree in gender and in number with the noun that it modifies:

Ella tiene mucha tarea.
She has a lot of homework.

Hay muchos coches.
There are many cars.

No tenemos muchas mesas.
We don't have many tables.

Muy

Muy is an adverb. You typically think of an adverb as modifying a verb, but in many cases muy is the kind of adverb that modifies an adjective. It translates to "very." Since it is an adverb, it does not have any other forms and does not change. Muy is placed in front of the adjectives that it modifies:

El maestro está muy enojado.
The teacher is very angry.

La montaña es muy alta.
The mountain is very high.

Muy doesn't only modify adjectives. It can also modify other adverbs as well:

¡Tú hablas muy bien!
You speak very well!

Mucho as an Adverb

Not to confuse matters, but mucho can also be used as an adverb. When used as an adverb it translates to "a lot," "much," or "often," and does not change its form. It is placed behind the verb:

Ella habla mucho.
She talks a lot.

¿Lees mucho?
Do you read much?

No venimos por aquí mucho.
We don't come here often.