I have written the first draft of a Middle Grade detective adventure in the vein of Enid Blyton's Famous Five or Astrid Lindgren's Bill Bergson. In my novel, the protagonist, a boy from England, is on holidays in France. He befriends a French boy, and together they solve a crime.
The English boy has learned French in school for a year, and a small part of the story is how he first struggles and later manages to communicate with the locals. Since the French boy doesn't speak English, much of the dialogue in my first draft is in French.
When I began to write, I liked the idea of showing the difficulties of getting along in a foreign country with only a rudimentary knowledge of the language. But now I believe that such a book is basically unpublishable. There are a few books for language learners that have foreign language dialogue in English text, but they are for more advanced learners and have more foreign language dialogue than my book has. Also, not every child learns French, and my audience would be severely limited. Therefore I want to revise the text and write all the dialogue in English.
As I see it, I have now three options:
Set the story in England. All persons are English. The language subplot is lost. Locations, names, cultural differences, etc. have to be changed into English places, names and so on.
Set the story in France. All persons are French. The language subplot is lost. The French setting remains. (Basically my novel will appear as if it was translated from French.)
Keep the story as it is, but give the French dialogue in English. Italics signify French (example is not from my text):
"Dad, this is Jean," Charlie introduced his new friend to his father.
"Hello, Jean," Charlie's father greeted Jean in French.
"Hello, Mr. Miller," Jean replied, and then added in strongly accented English: "Nice to meet you."
A few questions on this site deal with how to represent foreign language in fiction. But that's not the problem I have. I know how I want to represent foreign language (in italics). What I want to know is:
What would readers prefer? (And what would therefore probably sell best?)
Is the difficulty of getting along in a foreign language environment interesting to kids between 10 and 12? Does it add more to a detective adventrue story for them than it detracts?
I have never read a Middle Grade novel where the protagonist had to speak in a foreign language for most of the story. There is a lot of adult fiction where the protagonist has to get along in a foreign language environment (e.g. James Clavell's Shōgun or some science fiction stories), but maybe in Middle Grade fiction it is unsellable. Should I get rid of the foreign language problem subplot completely (and choose options 1 or 2)?
To clarify:
I have already decided not to write the dialogue in French. The question is which of the three options outlined above would be the best choice when it comes to marketability and increasing sales. None of the options contain any French dialogue!
What I miss in the answers I have recieved, is a source that substantiates that the proposed option is the best (or the sensible one). Sources could be examples from successfully published Middle Grade books, or a statement by a person from the publishing industry on this or a comparably similar matter.