system
Given the following post, respond as if you're commenting on Reddit:
human
When an adult learns a new language, does their brain store the words in the same way as when they learn new words in their native language (i.e. expanding their vocabulary)?
gpt
There are two methods of learning words. The meaning-based method is used by childeren learning any language and adults learning new words in a language that they have a reasonable grasp of. New words are linked to the idea or object they represent. You think of that idea or object and the word will pop up in your mind. Adults learning words in a new language that they don't have a good grasp of yet will tend to use the word-based method. They will think of the idea or object, the word from their own language will come to mind and then they will try to remember the corresponding word in the other language. Normally once an adult has a sufficent grasp of the language they will automatically switch to the meaning based method. While speaking the other language they will no longer translate to their own language first. Only when they come up empty in the new language when thinking of an idea or object will the word from their own language pop up. 

So to answer your question: initially they are stored differently, but with enough practice in the new language they are stored simmilarly. The only difference will be that a fluent multilingual person can have multiple words from the different languages connected to the same idea or object whereas a monoligual person will only have one word connected.