&gt;Monolinguals have less data to process<p>and Bilingual data is highly repetitive. And not every concept is useful - what use are german gendered pronouns? Add in that fact that as a tool for communication, you won&#x27;t be able to use you full vocabulary everywhere.<p>In addition, seems like there is an obvious difficulty wrt incompatible grammars.<p>There&#x27;s nothing preventing you expanding you current vocabulary in your native language (jargon) - why do you need to learn a new language?