In 1917 he entered as a regular student at Escuela Superior № 3, an important public school in Rancagua, however, he became ill with a convulsive cough and had to temporarily abandon his studies.

[1] In 1926 he wrote his first poems that were published in the magazine Don Fausto, a local newspaper, under the pseudonym "Raúl Gris", in tribute to his younger brother.

There are different versions about the circumstances of how they met for the first time and how this relationship was developed, related in some biographies and anthologies about the writer written by Pradel herself and other authors.

In 1946 he accepted a position at the Liceo Juan Antonio Rios in Santiago, where he began his work on March 8, 1947, and traveled continuously to Rancagua[citation needed].

However, despite the support of his fellow writers, his health was severely impaired and he entered the Hospital del Salvador on September 12, dying in Santiago on November 1, 1947.

Despite these contrasts and the evolution of his literature, in all his work a unique and personal voice is recognized under his unmistakable stamp, as described in Memoria Chilena: "clarity, transparency, humanism, love and eroticism, social justice and a neat and careful handling of language, of the precise word, of the just adjective ".

[12] At the end of the 1930s, Castro was considered in Chile as one of the representatives of the so-called "poetry of clarity ", a literary tendency partly inspired by the work of the recently deceased Federico García Lorca, and created as a response to the hermeticism and subjectivism of the historical avant - garde.

On the other hand, his narrative, which in stories like Llampo de Sangre (1950) are more realistic, close to criollismo has been a fundamental influence in the contemporary chilean literature, a raw vision that in the following decades would serve as a reference and inspire the work of chilean writers of the late twentieth century and early twenty-first century such as Pedro Lemebel,[1] Hernán Rivera Letelier,[1] Juan Radrigán,[1] Nona Fernández,[1] among others.