http://premon.fbk.eu/resource/vn33-comprehend-87.2-1-1-1_frame_3 an entity of type: VerbNetFrame

8.1 
NP V PP.stimulus what S 
understand(during(E), Experiencer, Stimulus) 
Experiencer V {about | of} Stimulus [+wh_inf] 
0.2 

data from the linked data cloud