It is quite common (in fact, nearly ubiquitous) for bilinguals to have different domains for each language. For example, you would probably prefer to have a computer conversation in English than in French, but you probably would prefer to speak to your family in French. It is also very common (again, nearly ubiquitous) for bilinguals to have varying degrees of competence in each language.<p>There isn&#x27;t an absolute boundary that separates bilinguals from monolinguals. If you&#x27;re interested in the topic, I&#x27;ve been reading this very interesting book. It&#x27;s slightly technical, but it&#x27;s a very interesting summary of many recent studies of bilingualism:<p><a href="http:&#x2F;&#x2F;ca.wiley.com&#x2F;WileyCDA&#x2F;WileyTitle&#x2F;productCd-EHEP002792.html" rel="nofollow">http:&#x2F;&#x2F;ca.wiley.com&#x2F;WileyCDA&#x2F;WileyTitle&#x2F;productCd-EHEP002792...</a>