The last edition of Marie De Garis' dictionary was published in 1982
Bill Gallienne and John De Garis began work on the fourth edition of the Dictiounnaire Angllais-Guernesiais in October 2009.
Bill said, "it's an absolute privilege" to be working on the update.
The main part of the work, Bill explained, lies in correcting the anomalies in the previous versions.
As well as that, Bill and John are adding some extra words that Marie has collected in the years since the last revision in 1982.
The dictionary was first published in 1967 and was entirely written and compiled by Marie De Garis. She was inspired to write the book as a youngster when she thought of writing down all the Guernsey French words she could find.
It seems this has never stopped through three editions of the dictionary, published between 1967 and 1982, and more recently Bill said: "Mrs De Garis is still collecting words now... she's still working on it even though she says she isn't."
Prior to the dictionary's publication the main text on Guernsey French was George Métivier's Dictionnaire Franco-Normand, however as this was written in the 1800s by the 1960s it no longer reflected the language according to Marie De Garis' introduction to her dictionary.
Marie De Garis was inspired to compile the dictionary as a child
Bill explained that when Marie first compiled the dictionary she used a system of index cards, he said: "I'm amazed how she did it... Every day when I'm working on this I think how on Earth did she ever do this?"
Bill and John started the work by transferring all of the information into a computer and updating and correcting any spellings and grammar issues this caused.
As well as adding words and correcting the anomalies Bill said he and John were fully revising the back half of the book to bring it in line with the front section, as in previous editions they did not "match up".
Technological innovations have seen many new words enter the English language since the dictionary was last published but Bill explained they were not going to try and put in translations for such modern words as there is "so much argument" about the subject, but he added the subject may be tackled in a new appendix.
Though the task was bigger than Bill first expected he hoped the new revised edition of the Guernsey French Dictionary would be finished by the end of 2010.