Having the ability to fluently speak more than one language comes with a lot of advantages. But how, exactly, do multilinguals manage to flip from one language to another without getting thoroughly confused?

According to a fantastic article shared by TWFH writer, Barbara Adams, research has shown that when a person who is multilingual speaks, all of the languages they know are active at the same time. For instance, when someone who is fluent in English, German, Spanish, and Italian wants to order a water in a restaurant in Italy, they will ask for “acqua,” but their brains are also activating “water,” “wasser,” and “agua.”

So, the question is, if the multilingual’s brain activates all languages at once, how does the person know which language to use? And how are they not constantly mixing them up?

It seems that the answer lies in the speaker’s language control process. When a multi-lingual person is tasked with speaking one language, all of the other languages they know are suppressed within their brain. However, when they need to quickly switch from one language to another, the portion of their brains that control the suppression show measurable energy spikes as they switch into the new language.

There are times, though, when the language control system fails and causes the speaker to mix in parts of one language into another. For example, an English-Spanish bilingual may be having a conversation in English, but inadvertently use “gato” instead of “cat.”

Amazingly, failure of the language control system can also cause a person to take longer to recall words in their first language than in other subsequent languages. This is what’s referred to as the reversed dominance effect.

In the reversed dominance effect, the multilingual’s brain sometimes suppresses their dominant language a little too much, in an effort to make the non-dominant languages easier to access. This can cause the dominant language to come out slower. It can also make it so that the speaker has a harder time retrieving words in their dominant language.

Pretty fascinating, isn’t it?

For more information on the amazing multilingual brain, be sure to check out this wonderful article from BBC.