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"Escribir" is a transitive verb which is often translated as "to write", and "ayer" is an adverb which is often translated as "yesterday". Learn more about the difference between "escribir" and "ayer" below.
escribir()
A transitive verb is a verb that requires a direct object (e.g., I bought a book.).
a. to write
Alejandra está aprendiendo a escribir su nombre.Alejandra is learning to write her name.
3. (to spell)
a. to write
Los nombres propios se escriben con mayúscula.Proper nouns are written with capital letters.
An intransitive verb is one that does not require a direct object (e.g., The man sneezed.).
a. to write
Es un verdadero escándalo que algunos niños terminen el colegio sin saber leer o escribir.It is truly shocking that some children leave school without being able to read or write.
escribirse
A reciprocal verb is a verb that indicates that two or more subjects perform an action on each other (e.g., Ellos se abrazan.).
a. to write to
Hace años que me escribo con un argentino que conocí cuando viajaba por Sudamérica.I've been writing to an Argentinian for years whom I met when I was traveling around South America.
ayer()
An adverb is a word that describes a verb, an adjective, or other adverbs (e.g., to run quickly, very tired).
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
2. (literary) (recent past)
A word or phrase restricted in usage to literature or established writing (e.g., sex, once upon a time).
a. yesteryear (literary)
A word or phrase restricted in usage to literature or established writing (e.g., sex, once upon a time).
La vida simple del ayer que echamos tanto de menos.The simple life of yesteryear that we miss so much.