Muy or mucho, and hablar claro

Muy or mucho

Muy goes in front of a describing word, an adjective or an adverb. Mucho goes with a verb or a noun, and before a noun it agrees:

Three things the table cannot show:

• Before mejor, peor, más and menos it is always mucho: mucho más caro - much dearer.
• The two never stack. Very much is muchísimo: Te quiero muchísimo. - I love you very much.
• Muy cannot stand alone. Answering a question, use mucho: ¿Estás cansado? Sí, mucho. - Are you tired? Yes, very.

For the rest of the degree ladder (bastante, demasiado, apenas, tan), see Spanish intensifiers.

Adjectives that work as adverbs

A handful of adjectives double as adverbs after certain verbs, with no -mente. In this use they never change, whoever does the verb:

The -mente form often exists too, and is more formal: trabajar duro (to work hard) is everyday speech, trabajar duramente is written style. Sometimes the meaning parts company: hablar alto is to talk loudly, while altamente means highly.

Phrases that do an adverb's job

Spanish often uses a fixed phrase where English uses one adverb. Learn them whole:

More of these, sorted by how often and how fast, are on Spanish idioms of time and frequency.