On the l-syntactic approach of Hale and Keyser (e.g. 1993), the position of the nominal that forms the Root of the denominal verb, prior to incorpor- ation, is identical to the position of certain unincorporated measuring-out arguments. Such roots may diVer in properties that bear on measuring-out, such as inherent boundedness. Consequently, we expect that diVerent denominal verbs will have diVerent Aktionsart properties, and that such properties will be reliably determined by the meanings of their roots, in the same way that such properties aVect the Aktionsart of VP predicates with unincorporated measuring-out arguments. This turns out to be the case. On this analysis, however, we must assume that there are two crucially diVerent types of denominal verb in English: verbs whose names are derived via incorporation of a Root from within the argument structure, producing the measuring-out eVect, and verbs whose names are derived some other way, by a mysterious, parametrically varying, ill-understood process which I shall call ‘Manner Incorporation’.