Examines the idea of a mismatch between grammaticality and acceptability. Evidence is used to refute the claim that ungrammatical but acceptable sentences are theoretically plausible in the case of the sentence, "A not unhappy person entered the room." (AMH)

Data from responses to a grammaticality judgement test by 26 learners of English as a second language at two proficiency levels were used to investigate syntactic acquisition. Four syntactic structures were examined. Results suggest that less proficient subjects use syntactic strategies, while more proficient learners use semantic-based…