One of my characters, when excited, switches between English, French, and Italian willy-nilly, sometimes a couple of times in a sentence. I used to hear people in Montreal do this. Does it have a name?
I don't think there's a word for it, because I do that IRL (I'm quadrilingual and my way of saying 'talking to you is like talking to the wall' is to swap languages) and no one has used a term for it on me.
Spanglish, Hinglish, any situation where a person is bilingual or polyglot and sentences are constructed with words and syntax from more than one language is called code-mixing or code-switching. I too am a polyglot and I do this all the time. There are even understood syntactic rules and expected points in a sentence where the code will cross over from one language to another, and points in a sentence where it almost never happens. The human brain, being hard-wired for language, waits for a spot where the transition will be least problematic and switches there instead of in a different spot.
My bilingual friend from Quebec City does this all the time when she comes to visit, and she always seems to forget that I don't speak French so I have no idea what she's talking about half the time!
True story: In a court interpretation dealing with a case of insurance fraud, the English phrase was we had to repair car, which I was then to interpret into Spanish for the defendant. It came out as tuvimos que remontirovar el carro. Everything stopped for a moment as all eyes were on me, which is rare because the interpreter is supposed to be "invisible". I did a mental rewind and realized what I had done. Remontirovat' is repair in Russian, not Spanish. I quickly fixed the error and everything moved forward. Later, between sessions, the judge asked me about the hiccup and I explained that I also speak Russian and that my brain grabbed the wrong file. Sorry. She laughed.
I really don't think there is a word for it, technically. Though I do it on occasion but, in a made up language for the most part. Also a bit of Russian by a couple of characters, but not very often seeing as it is written in English (American) over all. I think it would be a bit distracting if I was reading a book that jumped languages a lot, while written in another language primarily. Exception being a Spy/Thriller, or a Travel/Adventure story for the language to change for the sake of continuity accuracy. Now for the question that the OP title sparks in my weird mind: Can you dub your characters? Not really sure why this came to my thoughts, but I felt it needed to be asked just to find out the plausibility of it.
@Wreybies I do that sometimes myself, especially since my second and third language are French and Spanish respectively, and they get very close in places.
Be careful how you write this. This is one situation where you need to forget about reality and think about the reader and what they expect to see on the page. Most readers can handle language switching, especially for expressive phrases or swear words from other languages. That's fun and expressive and the reader can mostly get the gist by context, or using words that you can teach them through the course of the book. But just occasionally jumping into another language that the reader doesn't (and can't be expected) to speak fluently is just, well, it's asking a bit much. If she's supposed to just be unintelligible when she's doing this then just she squeaked excitedly in French is a better bet I think, because to most people it'll be close to impossible to scan. It's a cute thing to throw in and I agree that people really do do this kind of thing. But this is a different kind of speech that doesn't need to really be transcribed; it's imparting her mood without needing to know what she said. So you don't need to tell us what she actually said, at least not often. I feel for you, really I do. Because I wrote a book that did some amount of the same thing. My main characters boyfriend was Romani (ie gypsy) and speaks their language as well as English and a bunch of other stuff. And through the book he teaches his new girlfriend bits of the language; just as a cute thing that they do together, something that no-one but them can understand. And that's super fun to write, really it is. It's really cute and it's challenging and engaging to write too, just from a mechanical level. But it does not read well. Even just coming back to it after a few months out of contact with the language it's so painful just to check that it says what I originally intended it to. It's fine when they use the odd word, fine even when they use repeated phrases mixed with English. But even in places where you don't need to know the meaning to get the point, when they are smooching and giggling together or when they are talking dirty, just running into a wall of words that don't scan and some you sort of recognize but you still have to stop and sound out and even then don't know for sure if you're remembering it right; it's just not a good idea. French and Italian are a bit more grokable than Romani and understandably so. There's extremely thin resources on Romani and certainly no-one learns it at school (seriously, I am not exaggerating to say that there's maybe a thousand or so documented words total). But even so running into strings of words that most readers won't recognize and even if they do they won't be able to understand quickly just slows down their ability to comprehend and makes the text tiring to work with. So be careful. You can get away with doing this directly in the text a couple of times early on, which of course gives her a reason to explain her backstory as to why she speaks languages and where she grew up and so forth. But as you go on, tone it done a bit. It's done it's job, it's show us a thing about who she is. Using distinctive words or phrases or French and Italian nicknames and so forth, characterful things that give her dialogue a unique flavor, absolutely, but don't just keep throwing stuff at the reader that they won't understand without some specific purpose and after the first time we meet here this isn't telling us anything new.
@LostThePlot I admit, for my work I am using idioms. For example, where an American would say 'wouldn't touch that with a ten-foot pole' a Brit would say 'barge pole'. Now, in my case, I've got a character with lengthy practices in multiple languages. So he tends to literally translate idioms rather than slip on words.
That stuff is fine to use, particularly using phrases that are more expressive in another language. Especially if they are re-used and the reader can learn that phrase as the book goes along. It's really that specific thing of dropping in and out of another language knowing that the reader won't follow it that needs to be carefully used.
Thanks for all the replies. As @LostThePlot suggested, I'm only showing some examples to set up the way she speaks using very familiar words. After that, I might have a few more examples, but I'll keep everything in English with a description of the code-mixing (language jumping). @Wreybies's point that switches occur in particular places is something that I fear I will get wrong. Would these be at phrase boundaries, for example? I asked my wife (she's French Canadian) about this before posting and she told me that as children they were taught that it was a very bad thing to do. It was a lazy way of talking. @Cave Troll, what do you mean by Can you dub your characters? I used to take the bus to work and frequently two twin girls would sit nearby, switching from French to English every few seconds. They would talk excitedly, finishing each other's sentences in a different language. It's unlikely I could capture the charm of their speech, but that's my model.
The linguistic term is code-switching. It's one of the few terms I still remember from my linguistics courses because I do that all the time. I'm not sure if I'd replicate this in writing. Maybe if I wrote in another language than English, and the character switched from the main language of the book to English every now and then. But if I wrote in English, I think I'd have to be more careful to write it in a way that the reader, whose first language would most likely be English, would still understand the meaning from the context.
There are five languages at play in my work, Latin, Greek, Aramaic, Chinese and Bactrian (ancient Pashtu/Urdu). The Latin dialogue is basically written as flowing colloquial American English, except when spoken by a Chinese speaker, where it comes across as pidgin - analytic grammarless Chinese coping with complex Latin syntax. Greek I capture as a bit more formal, more like high class British English with no slang or contractions, as that is how the Latin speakers would use it. Aramaic uses a King James style English, "Thous sayest" just to differentiate it and make sure the reader understands that the Latin speakers may not understand what is being said. My Latin (and other) speakers, when learning Chinese, initially speak very haltingly among themselves, groping for words, but I don't drag that out... the next chapter is just enough to indicate they are still struggling, then thereafter they are speaking well. Similarly with Bactrian, though that is an Indo-European language and they will find cognate words and recognizable grammar sequences, again, the transition not drawn out. In all cases, there is a native speaker to help their learning... There was no Rosetta Stone courseware 2000 years ago.