Research into how multilingual people juggle more than one language in their minds is complex and sometimes counterintuitive. It turns out that when a multilingual person wants to speak, the languages they know can be active at the same time, even if only one gets used. These languages can interfere with each other, for example intruding into speech just when you don’t expect them. And interference can manifest itself not just in vocabulary slip-ups, but even on the level of grammar or accent.
“From research we know that as a bilingual or multilingual, whenever you’re speaking, both languages or all the languages that you know are activated,” says Mathieu Declerck, a senior research fellow at the Vrije Universiteit in Brussels. “For example, when you want to say ‘dog’ as a French-English bilingual, not just ‘dog’ is activated, but also its translation equivalent, so ‘chien’ is also activated.”
How they do this is commonly explained through the concept of inhibition – a suppression of the non-relevant languages. When a bilingual volunteer is asked to name a colour shown on a screen in one language and then the next color in their other language, it is possible to measure spikes in electrical activity in parts of the brain that deal with language and attentional awareness.
