Blub
I think the way they talk and pronounce the word is different and that’s how i differentiate them even when i don’t know a word from both language.
I speak 3 languages daily and as for my case it’s only when i speak it’s tough to remember the word of that language i want if the code switch isn’t quite “right” so sometimes a word or two from another language will seep through. Never get confuse on what language is spoken by others though
This my fav
https://youtu.be/Ah597mW9LXA