Introduction 2 Verbal prefixes 2.1 R Russian SK Slovak SL Slovenian US Upper Sorbian 'become ill' 'start running' (2) a. prze-robić b. prze-pisać overdo over-write 'rework' 'rewrite' (3) a. na-begat'sja b. na-laufati se c. na-běhat se on-run.self on-run self on-run self all mean: 'come to have one's fill of running' Compositional (spatial) lexically prefixed verbs are cases like the Serbo-Croatian nabàcati in (4a), the Old Church Slavonic naiti in (4b) and the Polish namalować in (4c). Consider also the Russian vpisat' in (5a), the Czech vnést in (5b) and the Slovak vliať in (5c). (4) a. na-bàcati b. na-iti c. na-malować on-throw on-walk on-paint 'throw sth. on sth.' 'walk on sth.' 'paint sth. on sth.' ('find') (5) a. v-pisat' b. v-nést c. v-liať in-write in-carry in-pour 'write sth. in sth.' 'carry sth. in sth.' 'pour sth. into sth.' The examples show that the superlexical prefixes in (1)-(3) and lexical prefixes in (4) and (5) behave consistently and that the meaning of the prefixed verbs is composed of the meaning of the verb and the meaning of the prefix/preposition. In contrast, the changes induced by lexical 'carry' 'carrying' (8) a. pis-a-ć b. pis-m-o write-TH-INF write-NMLZ-NOM.SG.N 'write' 'writing, magazine' (9) a. běl-at b. běl-it white-TH-INF white-TH-INF 'become white' 'make white' 'he/she/it will swim in sth. / swim out of sth. / swim away from sth. / swim to sth. / 'become ill one after another' 'alter/redo one after another' c. po-roz-děl-á-va-t po-apart-do-TH-SI-INF 'disassemble one after another' The fact that superlexical prefixes have an adverbial meaning and can scope over the secondary imperfective suffix is the reason why some researchers propose that superlexical prefixes are generated in or above the aspectual phrase. 5 Note, however, that superlexical prefixes could, in fact, also merge lower in the verbal structure-being an overt reflection of some higher operator-and later move. It is a well-known fact that it is necessary to distinguish between lexical aspect and