摘要:Humans are intuitively good at providing judgments about what forms part of their native language and what does not.Although such judgments are robust, consistent, and reliable, human cognition is demonstrably fallible to illusions of various types.Language is no exception.In the linguistic domain, several types of sentences have been shown to trick the parser into giving them a high acceptability judgment despite their ill-formedness.One example is the so-called comparative illusion (‘More people have been to Tromsø than I have’).To this day, comparative illusions have been tested mainly with monolingual, neurotypical speakers of English.The present research aims to broaden our understanding of this phenomenon by putting it to test in two populations that differ in one crucial factor: the number of languages they speak.A timed acceptability judgment task was administered to monolingual speakers of Standard Greek and bi(dia)lectal speakers of Standard and Cypriot Greek.The results are not fully in line with any of the semantic re-analyses proposed for the illusion so far, hence a new proposal is offered about what interpretation induces the illusion, appreciating the influence of both grammatical processing and cognitive heuristics.Second, the results reveal an effect of developmental trajectory.This effect may be linked to an enhanced ability to spot the illusion in bi(dia)lectals, but several factors can be identified as possible culprits behind this result.After discussing each of them, it is argued that having two grammars may facilitate the setting of a higher processing threshold, something that would entail decreased fallibility to grammatical illusions.