<i>The</i> swarm <i>-alternation in</i> <i>R</i> <i>omance languages: the fine line between causes and sources</i>

Abstract The swarm -alternation shows two variants, where the locatum and location alternate their positions: in the locatum-subj variant ( The bees swarm in the garden ), the locatum appears in subject position, whereas the location surfaces as a PP. In turn, in the location-subj variant ( The garden swarms with bees ), the location appears as the subject, and the locatum is introduced by a preposition ( de/di “of” in Spanish, Catalan, and Italian). We argue that the locatum-PP is, in fact, the element introducing the initiator of the event in the latter variant. This is so because the subject is a non-theta selected element, functioning as the undergoer of the event; hence, it does not meet the requirements to initiate it. As to the locatum-subj variant, the locatum subject works as the initiator and undergoer of the event. Furthermore, we show that the argument structure of these verbs consists of both process and initiation phrases in Ramchand’s first phase syntax. While the location-subj variant is consistently unergative, the locatum-subj variant can also be unaccusative as is the case with verbs such as overflow or abound .