vs 

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"Si" is a form of "si", a conjunction which is often translated as "if". "En caso de que" is a phrase which is often translated as "in the event that". Learn more about the difference between "si" and "en caso de que" below.
si(
see
)
A conjunction is a word that connects words, phrases, clauses, or sentences (e.g., The cat and the dog slept.).
conjunction
a. if
Si llueve mañana, cancelaremos el pícnic.If it rains tomorrow, we will cancel the picnic.
a. whether
Preguntó si me estaba divirtiendo.He asked whether I was enjoying myself.
b. if
Paco quiere saber si Laura también va a asistir.Paco wants to know if Laura is also going to attend.
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
masculine noun
a. B
Primero lo oí en si menor.I first heard it played in B minor.
b. ti (solfége)
Practiquemos las escalas en orden inverso: do, si, la...Let's practice scales in reverse order: do, ti, la...
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en caso de que(
ehn
 
kah
-
soh
 
deh
 
keh
)
A phrase is a group of words commonly used together (e.g., once upon a time).
phrase
a. in the event that
En caso de que el vuelo sea cancelado, pueden tomar el siguiente.In the event that your flight is canceled, you can take the following one.
b. in case
Lleva una campera en caso de que refresque.Take a jacket in case it gets colder.
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