shakes you vigorously for its duration 
(ROOT (VP (VBZ shakes) (NP (PRP you)) (ADVP (RB vigorously)) (PP (IN for) (NP (PRP$ its) (NN duration)))))
(ROOT (VP (VBZ ) (NP (PRP )) (ADVP (RB )) (PP (IN ) (NP (PRP$ ) (NN )))))