I found this thread in my search, but it didn't cover completely what I wanted to know.

My dog knows 3 hand signals reliably right now, and all her commands are in English.
She's about 2 years old, still very capable of learning commands in a different language. But is there a way to train her to respond only to a command in a certain language?

I've noticed a lot of dog owners around me are frustrated because their dogs will respond to anyone giving them a command and one friend in particular has a mother who is in a constant state of meddling with her training and giving the dog commands that the dog follows and interrupts the original command.
She's teaching her dog commands in Latin because her mother doesn't know Latin and she remembers it from HS, which I thought was neat. But we were curious... is it possible to "phase out" a command they already know in English so they do not respond to it at all anymore unless spoken in the re-trained language?

I thought it would be nice to train my dog in French or German so guests or roommates couldn't give her commands constantly that conflicted with mine. I'll give her a sit command and someone walks in the door and immediately calls "Diaz, come!", and she breaks sit to run to them, which to me says I obviously have not trained her well enough to sit without distraction and she doesn't see me as the "primary" alpha. (although most times when someone gives her another command and I'm around, she looks to me for a signal that it's OK to do the command, which is better than her running off without a second glance) I'm working on it, but it can be difficult because when my roommates give her a command she'll listen, which isn't BAD I don't think in most cases (if they need her to lay down, I don't see a problem) but I also become aggravated because my training is interrupted when they give her commands and confuse her. She tries to follow my command, but also wants to follow what someone else said because she knows that command. Part is a matter of training people to not interrupt when I'm giving her commands, but it doesn't stop it from happening when a guest comes over that doesn't know the rules or when friends of my roommates drop in.

It almost seems like it might confuse the dog too much to try and phase out a well-established command and I don't want to do that, but it would be neat if the commands in English could be phased out entirely so the dog only responds in whatever chosen language. For the case of my friend and her Latin Corgi, she just wants it so her mother won't barge in and give the release command after only 30 seconds of sit-stay and have to confuse the dog more or restart the entire session. Do you guys think it's possible, or would it just cause too much confusion for the dog?

It certainly IS possible. You are right in that the humans around need to respect your training time.

You may want to establish a time when you'll be training your dog, and get your roommate to agree that such times are "off-limits" for any sort of interaction with your dog. If you get buy-in from those around you, the re-training of your dog will go well AND you'll be retraining THEM as well.

You'd mentioned that you don't think the dog sees you as alpha. Well, the great news is that you can start building/rebuilding that relationship right away!

When you are in the pack leader role, the dog will look more and more to you for cues on how to act. That she looks to you before dashing off to somebody is a good thing. Keep a drag-line on her, and when somebody gives her a command, just step on the end of the drag line in such a way that it does nothing to Diaz except prohibit her from following that command. Then, when she looks at you, praise her and give your chosen language "stay/down/whatever" command.

Luck!
-Jim

With German, words like Sit/Sitz; Come/Komme are so similar to our language, I think it would be difficult.

You might want to consider making up your own words, possibly?

Real short post.

If you want to train your dogs for a diffrent command (they know hand commands right?) just start giving the new command with the hand commands and over time you will be good to go.

as far as your dog taking orders from other people give him a correction every time he does something for someone else teach him/her that you are the only one that is alpha to him.

if you have any questions feel free to PM me i got to get to bed!