Construction Grammar, Frame Semantics and LVC alternation in Persian Ali Safari, Tehran University In this study we show that with Frame Semantics as a descriptive tool, Construction Grammar allows us to analyze the verb meaning in more detail. Focusing on argument alternation of some Light Verb Constructions (LVC) in Persian, we show how a frame-based description of verbal polysemy may be used to explain a range of argument structures associated with a verb. In Persian a number of LVCs consisting of a light verb and a preverb (PV) participate in causative alternation. The causative variant is formed with the LV ændaxtæn 'cause to fall' and the anti-causative variant is formed with oftadæn 'fall' (1). But in some cases the anti-causative variant is not acceptable by native speakers of Persian, although the causative variant is acceptable (2). Karimi-Doostan (2005) claim that the argument structure of LVCs is determined by PVs while Folli, Harley & Karimi (2005) propose that both PVs and LVs compositionally contribute to the a-structure of LVCs. Using the notion of Frames (Fillmore & Baker, 2010) We propose that the whole LVC Construction including the LV determines its a-structure. Goldberg (1995, 2002, 2006) introduces a constructional approach to argument structure and argues that some argument structures can be regarded as independently existing grammatical constructions. In her analysis, a verb can occur in a constructional pattern when the event type encoded by the verb is compatible with the one encoded by the construction in certain ways. Concerning the causative alternation, we can characterize the causative form as an instance of causative construction and its intransitive counterpart as an instance of anti-causative construction. According to her analysis, causative construction involves argument roles cause and patient. The anti-causative construction involves the argument role patient. Her theory attributes different meanings of full expressions to the constructions involved but based on her theory we cannot explain the different behavior of LVCs in (1) and (2). Since LVCs are the same in (1) and (2), based on Goldberg's theory it is not clear why it can participate in causative alternation in (1) but it cannot in (2). Following Nemoto (2005) I argue that verbs can be associated with more than one semantic frame. In this case the two uses of ændaxtæn seem to be linked to two distinct frames. This difference may underlie the contrast in (3). We will refer to different frames of this LV as ændaxtæn-change of state (4) and ændaxtæn-change of location (5). When the full expression including occurs in change of state frame the event encoded by the LVC is compatible with both causative and anti-causative constructions. Participant roles of ændaxtæn-change of state fuse with the argument roles of causative and anti-causative constructions. When the full expression occurs in change of location frame, the event is just compatible with causative construction hence no anti-causative variant. Participant roles of ændaxtæn-change of location fuse with the argument roles of causative construction but they cannot fuse with argument roles of anti-causative construction.