vs
QUICK ANSWER
"Graves" is a form of "gravar", a transitive verb which is often translated as "to tax". "Muy grave" is a phrase which is often translated as "very serious". Learn more about the difference between "muy grave" and "graves" below.
muy grave(
mwee
grah
-
beh
)A phrase is a group of words commonly used together (e.g., once upon a time).
a. very serious (situation or events)
La situación en el país es muy grave, y la guerra civil podría estallar en cualquier momento.The situation in the country is very serious, and a civil war might break out any moment now.
b. seriously ill (sick person)
Han hospitalizado al padre de Ana porque está muy grave.Ana's father has been admitted to hospital because he's seriously ill.
2. (weighty)
a. very serious
Conducir ebrio constituye una falta muy grave.Driving while intoxicated is a very serious misdemeanor.
a. very grave
El Primer Ministro anunció la muerte del rey en tono muy grave.The Prime Minister announced the king's death in a very grave tone.
gravar(
grah
-
bahr
)A transitive verb is a verb that requires a direct object (e.g., I bought a book.).
a. to tax
El país grava las importaciones de los Estados miembros.The country taxes imports from Member States.
b. to levy a tax on
Gravar las bebidas alcohólicas para recaudar más dinero no tiene muchos apoyos.Levying a tax on alcoholic drinks to increase receipts is not widely supported.
c. to mortgage (real estate)
El gobierno está estudiando a gravar las viviendas vacías.The government is considering mortgaging empty homes.
a. to burden
El mantenimiento de un coche grava mucho los gastos mensuales de una familia.The maintenance of a car burdens much of the monthly expenses of a family.
gravarse
A pronominal verb always uses a reflexive pronoun. (e.g., Te ves cansado.).
a. to get worse
El estado del paciente se gravó pese a estar en cuidados intensivos.The patient's state got worse despite being in intensive care.