vs
QUICK ANSWER
"Formal" is an adjective which is often translated as "formal", and "casual" is an adjective which is often translated as "chance". Learn more about the difference between "formal" and "casual" below.
formal(
fohr
-
mahl
)An adjective is a word that describes a noun (e.g., the big dog).
a. formal
Como es de noche, creo que la boda va a ser formal.Since it's at night, I think the wedding will be formal.
a. reliable
Sebastián es muy formal y siempre llega a tiempo.Sebastian is very reliable and is always on time.
b. dependable
Gloria es muy formal; siempre hace lo que la situación exige.Gloria is very dependable; she always does what the situation demands.
c. responsible
Verónica es menor que su hermano, pero es más formal.Veronica is younger than her brother, but she is more responsible.
d. serious
Gustavo es muy formal en el aspecto de cumplir con sus promesas.Gustavo is very serious in the sense that he keeps his promises.
casual(
kah
-
swahl
)An adjective is a word that describes a noun (e.g., the big dog).
1. (accidental)
a. chance
El encuentro casual con el director de la empresa donde quería trabajar fue muy oportuno.My chance meeting with the CEO of the company I wanted to work at was very timely.
b. accidental
Fue un descubrimiento casual, pero me han dado el mérito.It was an accidental discovery, but they've given me credit for it.
2. (colloquial) (relaxed) (Latin America)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
Regionalism used in Latin America: all the countries in South America, Central America, and the Caribbean. Does not include Spain.
a. casual
Mi fiesta de graduación fue una reunión muy casual.My graduation party was a very casual get-together.
a. case
En algunos idiomas, hay sufijos casuales que indican la función gramatical de un sustantivo.In some languages, there are case suffixes that indicate the grammatical function of a noun.