Before a nounnounA word that names a person, thing, place, or idea, such as house or sun.: mucho and poco agree
Before a nounnounA word that names a person, thing, place, or idea, such as house or sun., mucho and poco agree in gendergenderThe grammatical class of a Spanish noun: masculine or feminine. and number – like an adjective ending in -o: mucho tiempo, mucha gente, muchos amigos, muchas casas; poco dinero, poca fruta, pocos libros, pocas personas.
Look at the nounnounA word that names a person, thing, place, or idea, such as house or sun., not at the meaning: la gente is femininefeminineA noun's gender that typically takes la or una in Spanish. and singularsingularThe grammatical form used for exactly one person or thing., so it's mucha gente. el agua is femininefeminineA noun's gender that typically takes la or una in Spanish. too, so Bebo mucha agua.
bastante and bastantes
bastante has no separate form in -a. Before a nounnounA word that names a person, thing, place, or idea, such as house or sun. it only changes for number: bastante dinero, bastante fruta, but bastantes libros, bastantes personas.
With a verb: always the same
With a verb, mucho, poco and bastante say how much someone does something. Then they never change – no matter who is doing it: Trabajo mucho. Mis amigas trabajan mucho. Duermo poco. Estudiamos bastante.
Before an adjective: muy, poco, bastante
Before an adjective, muy, poco and bastante show how strong something is. Here, too, they never change; only the adjective agrees: La casa es muy bonita. Las clases son bastante fáciles. Before an adjective, poco means "not very": La película es poco interesante. (The film isn't very interesting.)
muy or mucho?
muy only goes before an adjective or adverb: muy grande, muy bien, muy cerca. mucho goes with a verb or before a nounnounA word that names a person, thing, place, or idea, such as house or sun.: Trabajo mucho. Tengo muchos amigos. That's why "mucho grande" is wrong, and after a verb at the end of a sentence you never use muy on its own: not "Trabajo muy.", but Trabajo mucho.
Examples
- Tengo muchos amigos.
- Bebo mucha agua.
- Como bastante fruta.
- Trabajo mucho.
- Es muy fácil.