In Creek, a Muskogean language, nominalization is formally signalled by a loss of inflectional morphology and the occurrence of derivational morphology. A nominalization may be taken to be a concrete interpretation of the event itself or one of its participants. The verbal derivational morpheme {ip} signals medio-passive voice, in which the executor of the event is not the agent of the event. The verbal derivational morpheme {ec} signals increased transitivity, by which transitive verbs are derived from intransitive, transitive verbs are made more transitive through an increase of some parameter of transitivity, and causatives are created with the help of the medio-passive morpheme. The middle-voice {k} morpheme signals that the executor of the event is affected by the action of the event, as in statives, intransitives, and reflexives. Participant agreement type is lexically marked for verbs, but paradigmatic contrast shows the markers to be semantically motivated. Types I and II marking vary with respect to control of the event, and Types II and III marking vary with respect to envelopment by the event. When the dependent verb of a modificational clause is non-tensed, the {ii} and {aa} suffixes differentiate non-identifiable from identifiable participants, respectively. When the dependent verb is tensed, the {ii} and {aa} suffixes differentiate mentioned events from asserted events, respectively. The semantic connection between the two uses of {ii} and {aa} are backgrounding and foregrounding, respectively. Non-identifiable participants and mentioned events are united in backgrounding and are suffixed with {ii}. Identifiable participants and asserted events are united in foregrounding and are suffixed with {aa}. {t} and {n} signal foregrounding and backgrounding, respectively, within the proposition; that is, they determine how a participant or event is foregrounded or backgrounded with respect to other participants or events within the same proposition. The {ooM} suffix backgrounds participants and events with respect to other propositions, as in answering questions, or with respect to the ontology of the participant or event itself.