if your alters are the dissociative kind there is an easy way to figure this out. dissociative alters dont come into being just out of the blue, they begin in very early childhood before the age of 5. so any time something unexpected happens all you need to do is look back on your life and see when that was going on in your life....

example when one of my alters to me seem to suddenly speak a different language my treatment provider and I were able to track that back in my life to before I was 5 years old. I had been watching sesame street whichis broadcast in many different languages and teaches very young children to speak different languages including but not limited to english, french, german, spanish, japaneese and even sign language. because of this I had picked up the spoken language skills that were broad cast on tv. just like any child learns from tv how to count and say their abc's spell and many other things. due to trama these very early and normal skills children have, in me got dissociated as part of my alters.

my treatment provider was also able to look back at my elementary, jr high and high school records which verified my very early skills of languages. I still have a problem with writing in other than my native languages and need interpretors and translators because I dont remember all those skills I used to have and I am relearning. not to mention Im an adult now so I dont use child/ teen foreign languages which is a lot easier to understand because children and teens incorporate english words into their other languages too and child words in many languages sound real close if not the same as english. example adults dont say....I fly over water to the plane place and rode in a car to mi home. (not to mention Mi in many languages does not mean the word "my" or "me" adults say ...I boarded my flight to John F kennedy airport then took a taxi home.

also something to understand different languages have different phrases and sentence structure, some even have the words out of order and little accent marks that totally change the word and meaning.

by using this my treatment provider and I could also tell when someone was pretending to speak another language by copying words into a search bar on the internet, versus actually knowing the language.

example Im native american and grew up in the native american culture. one of my alters attempted to pretend to speak another language but did not know that the little curly que, and accents changed the sound of the words and meanings of the words spoken. so when they were attempting to say I feel this or that, what they were actually doing was telling their therapist to go you know what you know where and that they a female alter had been wearing a male under garment meant for incontinent / impotent men over 80 in the hindu culture that was discontinued back in the 1920's and that they died on the Hindenburg lol.

there is also the fact that each spoken language has their own culture, body languages, facial expressions, how their muscles work, how the breathing works while talking. mannerisms... example just like with speaking english some words are said with the tongue touching the teeth, in french the mouth barely opens, or the tongue touches the side or in spanish language the tongue curls to make the rolling sounds...the muscles in the neck on some languages dont move at all and others move greatly, sometimes the muscle under the ear twitches, in some languages the eye brows move a certain way to convey a certain word... theres actually a great deal that goes into speaking and writing foreign languages that most people do not know about unless you have grown up in that language. thats why english is so hard for me at times. I cant always get things exactly right and then people look at me confused because my words may say one thing but in reality what I am showing is something completely different. even people online can tell most times that english is not my native language because I dont "speak" it in normal natural vocabulary, phrasing and such that english natives do.

in the end this alters pretending to be another language and culture did not get past even one therapy session.

my suggestion is talk with your treatment provider. they will be able to help you research your life to track down if this speaking another language is for real for you or like mine just an alter pretending, or if there is documentations through out your life time that this other language was a native language for you and it just got dissociated.

if it just got dissociated then its very easy to get it back. it took nothing for me to learn the child languages that I knew in childhood that got dissociated. it was just a matter of hearing that alter speak those words and it all got integrated back together with me.

remember integration is just gaining back what was lost. combining with your own awareness. the fact that you heard, and recognized this alter was speaking another language means integrating that has already begun. if it wasnt then you still would not have heard the alter speaking it and recognizing it as a foreign language. it would still be unintegrated/ meaning dissociated out of your awareness. not co conscious with you.