Faulty Japanese sentences are judged more grammatical when punctuation is used: negative implications for Chomsky's principle of Full Interpretation

88 adult Japanese speakers judged the grammaticality of isolated simple bitransitive sentences involving an uninterpretable extra argument in addition to three legitimate arguments. The sentences thus violated Chomsky's principle of Full Interpretation which prohibits the structure building of a sentence including uninterpretable elements. The primary variable of interest was the presence or absence of punctuation, i.e., commas, which enclosed the extra argument. Findings showed that sentences with punctuation were judged more grammatical than the ones without punctuation, with an average score of judged grammaticality exceeding 3 on a 7-point scale (1 =least grammatical; 7=most grammatical). This score would not be expected if the speakers possess and judge the sentences in conformity with the principle of Full Interpretation.