Kaplansky began his career in education, teaching French and English as a second language before transitioning into professional translation. In 1999, while working in Ottawa, he published his first article in English on the translator Eleanor Marx in the journal Circuit. He has translated numerous literary works, including fiction, non-fiction, poetry, and youth literature. Kaplansky's translation of Lise Gauvin's writing has a dexterity and familiarity. His translation of Reading Nijinsky by Hélène Rioux "is surprisingly natural—the book's preoccupation with linguistic interplay lets it leap into English quite easily, and Jonathan Kaplansky has kept the narrative clean and meditative." His most notable translation is Things Seen (La Vie extérieure) by Annie Ernaux, published by the University of Nebraska Press in 2010, which Susan Salter Reynolds in The Los Angeles Times described as a "beautiful translation." In 2022, he translated the libretto for the opera Yourcenar: Une île de passions by Hélène Dorion and Marie-Claire Blais, which was performed by the Opéra de Montréal.
Kaplansky is an active member of the literary community and has served on the executive of the Literary Translators' Association of Canada (LTAC).
Awards and recognition
Wall Award Finalist (2007): Kaplansky's translation of Frank Borzage: The Life and Films of a Hollywood Romantic by Hervé Dumont, foreword by Martin Scorsese. McFarland, 2006.
French Voices Award (2010): Awarded to translate La Vie extérieure / Things Seen by Annie Ernaux.