This paper investigates the relative contribution of intonation and pauses in English-speaking listeners` interpretation of certain potentially ambiguous adverbs in English. When ``cleverly``, for example, is used in a sentence like ``The people in the basement (,) cleverly (,) opened the vent to the outside``, the adverb can be interpreted as having either a parenthetical/sentential reading (i.e., the people are judged to be clever to open the vent, as opposed to leaving it closed) or a manner reading (i.e., the people showed great cleverness in the way they opened the vent). Previous syntactic literature claimed that both the presence of heavy pausal breaks before and/or after the adverbs and a special pitch contour associated with the adverbs might influence listener`s interpretation of these adverbs. A perception experiment conducted in the current study indicates that the difference in pitch contour patterns, not the presence or absence of major intonation breaks, plays the major role in affecting listeners` interpretation of the adverbs. Implications of the current findings for the prosodic and syntactic representations of the parenthetical-manner ambiguous adverbs are discussed.