The purported Present Perfect Puzzle

The Present Perfect Puzzle (Klein 1992) asks why English sentences in the Present Perfect do not allow a speciVcation of the time of the event. The paper suggests an indirect answer to the question: in languages that do allow this, perfect morphology is ambiguous between a use that is semantically a true Perfect and one that corresponds to a Past (Preterit). A further puzzle in Klein’s paper relates to the English Past Perfect: what is wrong with At seven, Chris had left at six? In this case the present paper suggests a direct answer; it attributes the ill-formedness of this sentence to fact that the English Past Perfect is ambiguous. Klein (1992) raises two questions. Question I: Why doesn’t the English Present Perfect go with temporal adverbials denoting a deVnite Past interval?