In linguistics and translation theory it is generally assumed that every native speaker is able to rapidly detect any non-member of his/her linguistic community. A questionnaire was designed to test this assumption and to find out to what extent native speakers of English could identify a native English translator versus a non-native translator into English and a single translator versus a team of translators in a set of translations from Slovene into English. It emerged that native speakers of English cannot always discriminate between native versus non-native translators, or between single translators and teams of translators. This leads to the conclusion that the definition of the term ‘native speaker’ is still open and far from being final, and also that translation theory should be cautious when referring to the innate capacities of an ideal native speaker.