&gt; <i>But so far no one has seen a disadvantage either. Right?</i><p>No, researchers have found disadvantages to bilingualism.  Bilinguals tend to know fewer words in their first language than monolinguals [1].  Bilinguals also experience more tip-of-the-tongue moments [2,3] and are slower in picture-naming tasks than monolinguals [2].<p>[1] <a href="https:&#x2F;&#x2F;www.psychologytoday.com&#x2F;blog&#x2F;life-bilingual&#x2F;201306&#x2F;do-they-know-many-words" rel="nofollow">https:&#x2F;&#x2F;www.psychologytoday.com&#x2F;blog&#x2F;life-bilingual&#x2F;201306&#x2F;d...</a><p>[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Tip_of_the_tongue#Effects_of_bilingualism" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Tip_of_the_tongue#Effects_of_b...</a><p>[3] <a href="http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC2862226&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC2862226&#x2F;</a>